Photoelectric conversion film, photoelectric conversion element and electronic device

ABSTRACT

There is provided a photoelectric conversion film including a quinacridone derivative represented by the following General formula and a subphthalocyanine derivative represented by the following General formula.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Priority PatentApplication JP 2014-099816 filed May 13, 2014, and Japanese PriorityPatent Application JP 2015-000695 filed Jan. 6, 2015, the entirecontents of each of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a photoelectric conversion film, aphotoelectric conversion element and an electronic device.

BACKGROUND ART

Recently, a solid-state image sensor having a multilayer structure inwhich photoelectric conversion films made of an organic material arelaminated has been proposed.

For example, Patent Literature 1 discloses a solid-state image sensor inwhich organic photoelectric conversion films for absorbing each of bluelight, green light and red light are sequentially laminated. In thesolid-state image sensor disclosed in Patent Literature 1, a signal ofeach color is extracted by performing photoelectric conversion on lightcorresponding to that color in each of the organic photoelectricconversion films.

In addition, Patent Literature 2 discloses a solid-state image sensor inwhich an organic photoelectric conversion film for absorbing green lightand a silicon photodiode are sequentially laminated. In the solid-stateimage sensor disclosed in Patent Literature 2, a signal of green lightis extracted by an organic photoelectric conversion film, and signals ofblue light and red light that are separated using a difference of alight penetration depth by the silicon photodiode are extracted.

Meanwhile, in the field of solar cells, in order to implement highphotoelectric conversion efficiency, technology in which two types oforganic materials are mixed such that at least one material becomescrystal fine particles and a photoelectric conversion film is formed asa bulk hetero mixed film is proposed. Specifically, as disclosed inPatent Literature 3, technology in which a p type photoelectricconversion material and an n type photoelectric conversion material arecodeposited so that a photoelectric conversion film is formed as a bulkhetero mixed film is proposed.

CITATION LIST Patent Literature

-   PTL 1: JP 2003-234460A-   PTL 2: JP 2005-303266A-   PTL 3: JP 2002-76391A

SUMMARY Technical Problem

Here, since spectral characteristics of a photoelectric conversion filmformed as a bulk hetero mixed film by two types of organic materials areinfluenced by spectral characteristics of the two types of mixed organicmaterials, a wavelength band of light to be absorbed is likely to bewider. Therefore, in the photoelectric conversion film formed as a bulkhetero mixed film, it is difficult to selectively absorb light of aspecific wavelength range and it is difficult to have appropriatespectral characteristics as the photoelectric conversion film of asolid-state image sensor. Accordingly, it is difficult to increasesensitivity of such a solid-state image sensor using an organicphotoelectric conversion film.

In view of the above-described problems, the present disclosure providesa new and improved photoelectric conversion film capable of increasingsensitivity of a solid-state image sensor, a solid-state image sensorincluding the photoelectric conversion film, and an electronic deviceincluding the solid-state image sensor.

Solution to Problem

According to an embodiment of the present disclosure, there is provideda photoelectric conversion film including a quinacridone derivativerepresented by General formula (1), and a subphthalocyanine derivativerepresented by General formula (2).

In General formula (1), R₁ to R₁₀ are each independently selected fromthe group consisting of hydrogen, a halogen, a hydroxy group, an alkoxygroup, a cyano group, a nitro group, a silylalkyl group, a silylalkoxygroup, an arylsilyl group, a thioalkyl group, a thioaryl group, asulfonyl group, an arylsulfonyl group, an alkylsulfonyl group, an aminogroup, an alkylamino group, an arylamino group, an acyl group, anacylamino group, an acyloxy group, a carboxy group, a carboxamido group,a carboalkoxy group, a substituted or unsubstituted alkyl group, asubstituted or unsubstituted cycloalkyl group, a substituted orunsubstituted aryl group, a substituted or unsubstituted heteroarylgroup, and an aryl or heteroaryl group formed by condensing at least twoof the R₁ to R₁₀ that are adjacent to one another.

In General formula (2), R₁₁ to R₁₆ are each independently selected fromthe group consisting of hydrogen, a halogen, a hydroxy group, an alkoxygroup, a cyano group, a nitro group, a silylalkyl group, a silylalkoxygroup, an arylsilyl group, a thioalkyl group, a thioaryl group, asulfonyl group, an arylsulfonyl group, an alkylsulfonyl group, an aminogroup, an alkylamino group, an arylamino group, an acyl group, anacylamino group, an acyloxy group, a carboxy group, a carboxamido group,a carboalkoxy group, a substituted or unsubstituted alkyl group, asubstituted or unsubstituted cycloalkyl group, a substituted orunsubstituted aryl group, and a substituted or unsubstituted heteroarylgroup, where X is selected from the group consisting of a halogen, ahydroxy group, a thiol group, an imide group, a substituted orunsubstituted alkoxy group, a substituted or unsubstituted aryloxygroup, a substituted or unsubstituted alkyl group, a substituted orunsubstituted alkylthio group, and a substituted or unsubstitutedarylthio group, and where at least one of R₁₁ to R₁₆ representsfluorine.

According to another embodiment of the present disclosure, there isprovided a photoelectric conversion film including a transparentcompound that does not absorb visible light and that is represented byat least one of the following General formula (3) and General formula(4).

In General formula (3), R₂₁ to R₃₂ are each independently selected fromthe group consisting of hydrogen, a halogen, a hydroxy group, an alkoxygroup, a cyano group, a nitro group, a silylalkyl group, a silylalkoxygroup, an arylsilyl group, a thioalkyl group, a thioaryl group, asulfonyl group, an arylsulfonyl group, an alkylsulfonyl group, an aminogroup, an alkylamino group, an arylamino group, an acyl group, anacylamino group, an acyloxy group, a carboxy group, a carboxamido group,a carboalkoxy group, a substituted or unsubstituted alkyl group, asubstituted or unsubstituted cycloalkyl group, a substituted orunsubstituted aryl group, a substituted or unsubstituted heteroarylgroup, and an aryl or heteroaryl group formed by condensing at least twoof the R₂₁ to R₃₂ that are adjacent to one another.

In General formula (4), R₄₁ to R₄₈ are each independently selected fromthe group consisting of hydrogen, a halogen, a hydroxy group, an alkoxygroup, a cyano group, a nitro group, a silylalkyl group, a silylalkoxygroup, an arylsilyl group, a thioalkyl group, a thioaryl group, asulfonyl group, an arylsulfonyl group, an alkylsulfonyl group, an aminogroup, an alkylamino group, an arylamino group, an acyl group, anacylamino group, an acyloxy group, an imide group, a carboxy group, acarboxamido group, a carboalkoxy group, a substituted or unsubstitutedalkyl group, a substituted or unsubstituted cycloalkyl group, asubstituted or unsubstituted aryl group, a substituted or unsubstitutedheteroaryl group, and an aryl or heteroaryl group formed by condensingat least two of the R₄₁ to R₄₈ that are adjacent to one another, andwhere Ar₁ to Ar₄ are each independently one of a substituted orunsubstituted aryl group and a substituted or unsubstituted heteroarylgroup.

In addition, according to another embodiment of the present disclosure,there is provided a photoelectric conversion element that includes aphotoelectric conversion film; a pair of electrodes that are disposed atboth sides of the photoelectric conversion film, which is interposedtherebetween; and a hole blocking layer disposed between thephotoelectric conversion film and one of the electrodes, where adifference between an ionization potential of the hole blocking layerand a work function of the one of the electrodes is greater than orequal to 2.3 eV.

According to another embodiment of the present disclosure, since thephotoelectric conversion film can selectively absorb light of a specificwavelength band, it is possible to obtain appropriate spectralcharacteristics for the solid-state image sensor.

Advantageous Effects of Invention

As described above, according to one or more embodiments of the presentdisclosure, there are provided a photoelectric conversion film capableof increasing sensitivity of a solid-state image sensor, a solid-stateimage sensor including the photoelectric conversion film and anelectronic device including the solid-state image sensor.

Note that the effects described above are not necessarily limited, andalong with or instead of the effects, any effect that is desired to beintroduced in the present specification or other effects that can beexpected from the present specification may be exhibited.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows explanatory diagrams illustrating a solid-state imagesensor (A) including a photoelectric conversion element according to anembodiment of the present disclosure and a solid-state image sensor (B)according to a comparative example.

FIG. 2 is a schematic diagram illustrating an exemplary photoelectricconversion element according to an embodiment of the present disclosure.

FIG. 3A shows the graph of evaluation results of a change in spectralcharacteristics of Example 4.

FIG. 3B shows the graph of evaluation results of a change in spectralcharacteristics of Comparative example 7.

FIG. 3C shows the graph of evaluation results of a change in spectralcharacteristics of Comparative example 8.

FIG. 3D shows the graph of evaluation results of a change in spectralcharacteristics of Comparative example 9.

FIG. 3E shows the graph of evaluation results of a change in spectralcharacteristics of a reference example.

FIG. 4 shows the graph of IPCE measurement results of Example 8 andComparative example 19.

FIG. 5 shows the graph of spectral characteristics of BTB compounds.

FIG. 6 shows schematic diagrams illustrating a structure of asolid-state image sensor to which a photoelectric conversion elementaccording to an embodiment of the present disclosure is applied.

FIG. 7 is a cross sectional view illustrating an outline in a unit pixelof a solid-state image sensor to which a photoelectric conversionelement according to an embodiment of the present disclosure is applied.

FIG. 8 is a block diagram illustrating a configuration of an electronicdevice to which a photoelectric conversion element according to anembodiment of the present disclosure is applied.

DESCRIPTION OF EMBODIMENTS

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to the appended drawings. Note that,in this specification and the appended drawings, structural elementsthat have substantially the same function and structure are denoted withthe same reference numerals, and repeated explanation of thesestructural elements is omitted.

Hereinafter, description will be provided in the following order.

-   -   1. Outline of photoelectric conversion element according to an        embodiment of the present disclosure    -   2. First Embodiment    -   2.1. Configuration of photoelectric conversion film according to        first embodiment    -   2.2. Configuration of photoelectric conversion element according        to first embodiment    -   2.3. Example according to first embodiment    -   3. Second Embodiment    -   3.1. Configuration of photoelectric conversion film according to        second embodiment    -   3.2. Configuration of photoelectric conversion element according        to second embodiment    -   3.3. Example according to second embodiment    -   4. Third Embodiment    -   4.1. Configuration of photoelectric conversion element according        to third embodiment    -   4.2 Example according to third embodiment    -   5. Application example of photoelectric conversion element        according to an embodiment of the present disclosure    -   5.1. Configuration of solid-state image sensor    -   5.2. Configuration of electronic device    -   6. Summary

1. OUTLINE OF PHOTOELECTRIC CONVERSION ELEMENT ACCORDING TO ANEMBODIMENT OF THE PRESENT DISCLOSURE

An outline of a photoelectric conversion element according to anembodiment of the present disclosure will be described with reference toFIG. 1 . (A) of FIG. 1 is an explanatory diagram illustrating asolid-state image sensor including a photoelectric conversion elementaccording to an embodiment of the present disclosure. (B) of FIG. 1 isan explanatory diagram illustrating a solid-state image sensor accordingto a comparative example.

Hereinafter, in this specification, when it is described that “light ofa certain wavelength is absorbed,” it means that about 70% or more oflight of the wavelength is absorbed. In addition, in contrast, when itis described that “light of a certain wavelength is transmitted” or“light of a certain wavelength is not absorbed,” it means that about 70%or more of light of the wavelength is transmitted and about 30% or lessof the light is absorbed.

First, a solid-state image sensor according to a comparative examplewill be described. As illustrated in (B) of FIG. 1 , a solid-state imagesensor 5 according to a comparative example includes photodiodes 7R, 7Gand 7B, and color filters 6R, 6G and 6B formed on the photodiodes 7R, 7Gand 7B.

The color filters 6R, 6G and 6B are films that selectively transmitlight of a specific wavelength. For example, the color filter 6R is afilm that selectively transmits red light 2R of a wavelength of greaterthan or equal to 600 nm. The color filter 6G is a film that selectivelytransmits green light 2G of a wavelength of greater than or equal to 450nm and less than 600 nm. The color filter 6B is a film that selectivelytransmits blue light 2B of a wavelength of greater than or equal to 400nm and less than 450 nm.

In addition, the photodiodes 7R, 7G and 7B are photodetectors forabsorbing light of a wide wavelength band (for example, an absorptionwavelength of a silicon photodiode is 190 nm to 1100 nm). For thisreason, when each of the photodiodes 7R, 7G and 7B is used, it wasdifficult to individually extract a signal of each color such as red,green and blue. Therefore, in the solid-state image sensor according tothe comparative example, light other than light corresponding to eachcolor is absorbed by the color filters 6R, 6G and 6B, only lightcorresponding to each color is selectively transmitted to separatecolors, and a signal of each color is extracted by the photodiodes 7R,7G and 7B.

Accordingly, in the solid-state image sensor 5 according to thecomparative example, since most light is absorbed by the color filters6R, 6G and 6B, the photodiodes 7R, 7G and 7B may substantially use only⅓ of incident light for photoelectric conversion. Therefore, in thesolid-state image sensor 5 according to the comparative example, it wasdifficult to increase detection sensitivity of each color.

Next, a solid-state image sensor 1 including a photoelectric conversionelement according to an embodiment of the present disclosure will bedescribed. As illustrated in (A) of FIG. 1 , the solid-state imagesensor 1 including the photoelectric conversion element according to anembodiment of the present disclosure has a configuration in which agreen photoelectric conversion element 3G configured to absorb the greenlight 2G, a blue photoelectric conversion element 3B configured toabsorb the blue light 2B and a red photoelectric conversion element 3Rconfigured to absorb the red light 2R are sequentially laminated.

For example, the green photoelectric conversion element 3G is an organicphotoelectric conversion element that selectively absorbs green lighthaving a wavelength of greater than or equal to 450 nm and less than 600nm. The blue photoelectric conversion element 3B is an organicphotoelectric conversion element that selectively absorbs blue lighthaving a wavelength of greater than or equal to 400 nm and less than 450nm. The red photoelectric conversion element 3R is an organicphotoelectric conversion element that selectively absorbs red lighthaving a wavelength of greater than or equal to 600 nm.

Accordingly, in the solid-state image sensor 1 according to anembodiment of the present disclosure, each of the photoelectricconversion elements can selectively absorb light of a specificwavelength band corresponding to red, green or blue. For this reason, inthe solid-state image sensor 1 according to an embodiment of the presentdisclosure, there is no need to provide a color filter for separatingincident light into each color, and all incident light can be used forphotoelectric conversion. Therefore, since the solid-state image sensor1 according to an embodiment of the present disclosure can increaselight that can be used for photoelectric conversion to about three timesthat of the solid-state image sensor 5 according to the comparativeexample, it is possible to further increase detection sensitivity ofeach color.

Also, in the solid-state image sensor 1 according to an embodiment ofthe present disclosure, the blue photoelectric conversion element 3B andthe red photoelectric conversion element 3R may be a silicon photodiodethat performs photoelectric conversion on light of a wide wavelengthband (specifically, such as 190 nm to 1100 nm). In this case, the bluephotoelectric conversion element 3B and the red photoelectric conversionelement 3R separate colors into the blue light 2B and the red light 2Rusing a difference of a penetration depth of light of each wavelengthwith respect to the solid-state image sensor 1. Specifically, since thered light 2R has a longer wavelength and is less easily scattered thanthe blue light 2B, the red light 2R penetrates to a depth separated froma surface of incidence. On the other hand, since the blue light 2B has ashorter wavelength and is more easily scattered than the red light 2R,the blue light 2B penetrates only to a depth close to the surface ofincidence. Accordingly, when the red photoelectric conversion element 3Ris disposed at a position away from the surface of incidence of thesolid-state image sensor 1, it is possible to separately detect the redlight 2R from the blue light 2B. Accordingly, even when the siliconphotodiode is used as the blue photoelectric conversion element 3B andthe red photoelectric conversion element 3R, the blue light 2B and thered light 2R can be separated using a difference of a penetration depthof light and a signal of each color can be extracted.

Accordingly, in the photoelectric conversion elements 3G, 3B and 3Rincluded in the solid-state image sensor 1 according to an embodiment ofthe present disclosure, it is necessary to selectively absorb light of aspecific wavelength band corresponding to red, green or blue andtransmit light of a wavelength other than an absorption wavelength. Inparticular, the green photoelectric conversion element 3G that is theclosest to a plane of incidence has an absorption spectrum in which asharp peak is represented in a green band (for example, a wavelengthband of 450 nm to 600 nm), it is necessary to decrease absorption in aband of less than 450 nm and a band of greater than 600 nm.

In view of the above circumstances, the inventors of the presentdisclosure intensively studied a photoelectric conversion filmappropriate for the solid-state image sensor and completed thetechnology according to the present disclosure. When the photoelectricconversion film according to an embodiment of the present disclosureincludes a compound to be described in the following embodiment, it ispossible to selectively absorb light of a specific wavelength band andhave appropriate spectral characteristics as the photoelectricconversion film of the solid-state image sensor. Therefore, when thephotoelectric conversion film according to an embodiment of the presentdisclosure is used, it is possible to increase sensitivity and aresolution of the solid-state image sensor.

Hereinafter, such photoelectric conversion films according to first andsecond embodiments of the present disclosure will be described. Inaddition, a photoelectric conversion element according to a thirdembodiment of the present disclosure having an appropriate configurationas the photoelectric conversion element of the solid-state image sensorwill be described.

2. FIRST EMBODIMENT 2.1. Configuration of Photoelectric Conversion FilmAccording to First Embodiment

First, the photoelectric conversion film according to the firstembodiment of the present disclosure will be described. Thephotoelectric conversion film according to the first embodiment of thepresent disclosure is a photoelectric conversion film that includes aquinacridone derivative represented by the following General formula (1)and a subphthalocyanine derivative that is represented by the followingGeneral formula (2) and absorbs green light.

In General Formula (1) above, R₁ to R₁₀ each independently represent anysubstituent selected from the group consisting of hydrogen, a halogen, ahydroxy group, an alkoxy group, a cyano group, a nitro group, asilylalkyl group, a silylalkoxy group, an arylsilyl group, a thioalkylgroup, a thioaryl group, a sulfonyl group, an arylsulfonyl group, analkylsulfonyl group, an amino group, an alkylamino group, an arylaminogroup, an acyl group, an acylamino group, an acyloxy group, a carboxygroup, a carboxamido group, a carboalkoxy group, a substituted orunsubstituted alkyl group, a substituted or unsubstituted cycloalkylgroup, a substituted or unsubstituted aryl group, and a substituted orunsubstituted heteroaryl group, or an aryl or heteroaryl group formed bycondensing at least two or more of any adjacent R₁ to R₁₀.

In General Formula (2) above, R₁₁ to R₁₆ each independently representany substituent selected from the group consisting of hydrogen, ahalogen, a hydroxy group, an alkoxy group, a cyano group, a nitro group,a silylalkyl group, a silylalkoxy group, an arylsilyl group, a thioalkylgroup, a thioaryl group, a sulfonyl group, an arylsulfonyl group, analkylsulfonyl group, an amino group, an alkylamino group, an arylaminogroup, an acyl group, an acylamino group, an acyloxy group, a carboxygroup, a carboxamido group, a carboalkoxy group, a substituted orunsubstituted alkyl group, a substituted or unsubstituted cycloalkylgroup, a substituted or unsubstituted aryl group, and a substituted orunsubstituted heteroaryl group, X represents any substituent selectedfrom the group consisting of a halogen, a hydroxy group, a thiol group,an imide group, a substituted or unsubstituted alkoxy group, asubstituted or unsubstituted aryloxy group, a substituted orunsubstituted alkyl group, a substituted or unsubstituted alkylthiogroup, and a substituted or unsubstituted arylthio group, and at leastone of R₁₁ to R₁₆ represents fluorine.

Here, the photoelectric conversion film according to the firstembodiment of the present disclosure may be formed as a bulk heteromixed film. In this case, since the quinacridone derivative representedby General formula (1) serves as a p type photoelectric conversionmaterial and the subphthalocyanine derivative represented by Generalformula (2) serves as an n type photoelectric conversion material, abulk heterojunction is formed by the derivatives.

The bulk hetero mixed film is, for example, a film having amicrostructure in which one of the p type photoelectric conversionmaterial and the n type photoelectric conversion material forming a filmis in a crystal fine particle state and the other thereof is in anamorphous state, and an amorphous layer uniformly covers a surface ofcrystal fine particles. In such a bulk hetero mixed film, since an areaof a pn junction that induces charge separation is increased by themicrostructure, it is possible to induce charge separation moreefficiently and increase photoelectric conversion efficiency.Alternatively, the bulk hetero mixed film may be a film having amicrostructure in which both the p type photoelectric conversionmaterial and the n type photoelectric conversion material forming a filmare in a fine crystalline state and mixed.

Meanwhile, spectral characteristics of such a bulk hetero mixed film areinfluenced by spectral characteristics of both the p type photoelectricconversion material and the n type photoelectric conversion material tobe mixed. For this reason, when spectral characteristics of the p typephotoelectric conversion material and the n type photoelectricconversion material forming the bulk hetero mixed film do not match, anabsorption wavelength of light in the bulk hetero mixed film is likelyto be wider. Accordingly, the photoelectric conversion film formed asthe bulk hetero mixed film may not obtain appropriate spectralcharacteristics as the photoelectric conversion film in the solid-stateimage sensor.

When the photoelectric conversion film according to the first embodimentof the present disclosure includes the quinacridone derivative and thesubphthalocyanine derivative having spectral characteristics matchingthe quinacridone derivative, it is possible to have appropriate spectralcharacteristics as the photoelectric conversion film of green light inthe solid-state image sensor.

Specifically, in the subphthalocyanine derivative included in thephotoelectric conversion film according to the first embodiment of thepresent disclosure, at least one of R₁₁ to R₁₆ is fluorine and thereforespectral characteristics match the quinacridone derivative.Specifically, the subphthalocyanine derivative in which at least one ofR₁₁ to R₁₆ is fluorine decreases a maximum value of the absorptionwavelength to be a shorter wavelength, and therefore absorption of lighthaving a wavelength of greater than or equal to 600 nm can be decreased.Accordingly, since the photoelectric conversion film according to thefirst embodiment of the present disclosure has an absorption spectrum inwhich a sharp peak is represented in a green band (a wavelength band of450 nm to 600 nm), it is possible to implement appropriate spectralcharacteristics as the photoelectric conversion film of green light inthe solid-state image sensor.

In addition, in a process of manufacturing the photoelectric conversionelement and the solid-state image sensor, a process involving heating(for example, an annealing process) may be performed. When thephotoelectric conversion material included in the photoelectricconversion film has a low resistance, the photoelectric conversionmaterial migrates and spectral characteristics may be changed due toheat in such heating treatment. In particular, since a generalsubphthalocyanine derivative has a low heat resistance, when the processinvolving heating is performed on a photoelectric conversion filmincluding the general subphthalocyanine derivative, an absorbancesignificantly decreases.

In the subphthalocyanine derivative included in the photoelectricconversion film according to the first embodiment of the presentdisclosure, since at least one of R₁₁ to R₁₆ is fluorine, a heatresistance significantly increases. Accordingly, in the photoelectricconversion film according to the first embodiment of the presentdisclosure, since the photoelectric conversion material to be includedhas a high heat resistance, it is possible to suppress a change inspectral characteristics in heating treatment. Accordingly, in thephotoelectric conversion film according to the first embodiment of thepresent disclosure, it is possible to increase a degree of freedom inthe process of manufacturing the photoelectric conversion element andthe solid-state image sensor.

In addition, in the subphthalocyanine derivative represented by Generalformula (2), R₁₁ to R₁₆ may be substituted with fluorine so as to havesymmetry (line symmetry or point symmetry) or may be substituted withfluorine so as to have no symmetry.

In addition, in the subphthalocyanine derivative represented by Generalformula (2), X may be any substituent, as long as the substituent canbind to boron. However, it is more preferable that X be any substituentselected from the group consisting of a halogen, a hydroxy group, asubstituted or unsubstituted alkoxy group and a substituted orunsubstituted aryloxy group.

Here, in the subphthalocyanine derivative included in the photoelectricconversion film according to the first embodiment of the presentdisclosure, it is preferable that all of R₁₁ to R₁₆ be fluorine.Specifically, as will be demonstrated in the following example, in thesubphthalocyanine derivative in which all of R₁₁ to R₁₆ are fluorine, itis possible to further decrease a maximum value of the absorptionwavelength to be a shorter wavelength. Accordingly, since thesubphthalocyanine derivative represented by General formula (2) canfurther decrease absorption of greater than or equal to 600 nm, it ispossible to absorb green light more selectively.

In addition, in the subphthalocyanine derivative represented by Generalformula (2), it is preferable that levels of a highest occupiedmolecular orbital (HOMO) and a lowest unoccupied molecular orbital(LUMO) be levels at which a photoelectric conversion mechanism can besmoothly performed on the quinacridone derivative.

Specifically, when the subphthalocyanine derivative represented byGeneral formula (2) serves as the n type photoelectric conversionmaterial and the quinacridone derivative represented by General formula(1) serves as the p type photoelectric conversion material, it ispreferable that an LUMO level of the subphthalocyanine derivative bedeeper than an LUMO level of the quinacridone derivative. In otherwords, it is preferable that an absolute value of the LUMO level of thesubphthalocyanine derivative be greater than an absolute value of theLUMO level of the quinacridone derivative.

Here, as the photoelectric conversion mechanism in the photoelectricconversion film according to the first embodiment of the presentdisclosure, the following two mechanisms are considered.

One photoelectric conversion mechanism is a mechanism in which thequinacridone derivative serving as the p type photoelectric conversionmaterial is excited due to light and excited electrons move from thequinacridone derivative to the subphthalocyanine derivative serving asthe n type photoelectric conversion material. In this case, it ispreferable that the LUMO level of the subphthalocyanine derivative be alevel at which excited electrons that are excited in the quinacridonederivative can move to the subphthalocyanine derivative smoothly.Specifically, it is preferable that a difference between the LUMO levelof the subphthalocyanine derivative represented by General formula (2)and the LUMO level of the quinacridone derivative represented by Generalformula (1) be greater than or equal to 0.1 eV and less than or equal to1.0 eV. More specifically, the LUMO level of the subphthalocyaninederivative is preferably greater than or equal to −4.8 eV and less thanor equal to −3.5 eV, and more preferably, greater than or equal to −4.5eV and less than or equal to −3.8 eV.

In addition, the other photoelectric conversion mechanism is a mechanismin which the subphthalocyanine derivative serving as the n typephotoelectric conversion material is excited due to light and excitedelectrons move to the LUMO level of the subphthalocyanine derivative.Accordingly, holes can move from the quinacridone derivative serving asthe p type photoelectric conversion material to the subphthalocyaninederivative. In this case, it is preferable that an HOMO level of thesubphthalocyanine derivative be a level at which holes can move from thequinacridone derivative to the subphthalocyanine derivative smoothly.Specifically, the HOMO level of the subphthalocyanine derivative ispreferably greater than or equal to −7.0 eV and less than or equal to−5.5 eV, and more preferably, greater than or equal to −6.7 eV and lessthan or equal to −5.8 eV.

In addition, when a purpose of the photoelectric conversion film is toextract an electromotive force, such as in a solar cell, in order toincrease an open end voltage, it is necessary to increase such adifference by decreasing an HOMO level of the p type photoelectricconversion material and increasing an LUMO level of the n typephotoelectric conversion material. On the other hand, the purpose of thesolid-state image sensor in which the photoelectric conversion filmaccording to the first embodiment of the present disclosure is used isto extract a signal of light of a specific wavelength. For this reason,in the photoelectric conversion film according to the first embodimentof the present disclosure, it is preferable that the LUMO level of thesubphthalocyanine derivative (the n type photoelectric conversionmaterial) be set according to a relation with the LUMO level rather thanan HOMO level of the quinacridone derivative (the p type photoelectricconversion material). Specifically, as described above, it is preferablethat a difference between the LUMO level of the subphthalocyaninederivative and the LUMO level of the quinacridone derivative be greaterthan or equal to 0.1 eV and less than or equal to 1.0 eV.

Here, specific examples of the subphthalocyanine derivative representedby General formula (2) are represented by the following compounds 1 to9. However, the subphthalocyanine derivative included in thephotoelectric conversion film according to the first embodiment of thepresent disclosure is not limited to the following compounds.

As described above, since the photoelectric conversion film according tothe first embodiment of the present disclosure includes the quinacridonederivative represented by General formula (1) and the subphthalocyaninederivative represented by General formula (2), it is possible toselectively absorb green light (for example, light having a wavelengthof greater than or equal to 450 nm and less than 600 nm). In addition,in the photoelectric conversion film according to the first embodimentof the present disclosure, since the quinacridone derivative and thesubphthalocyanine derivative to be included have a high heat resistance,it is possible to suppress a change in spectral characteristics in theprocess of manufacturing the photoelectric conversion element and thesolid-state image sensor. Accordingly, since the photoelectricconversion film according to the first embodiment of the presentdisclosure can be appropriately used for the green photoelectricconversion element of the solid-state image sensor, it is possible toincrease sensitivity of the solid-state image sensor.

2.2. Configuration of Photoelectric Conversion Element According toFirst Embodiment

Next, the photoelectric conversion element according to the firstembodiment of the present disclosure will be described with reference toFIG. 2 . FIG. 2 is a schematic diagram illustrating an exemplaryphotoelectric conversion element according to the first embodiment ofthe present disclosure.

As illustrated in FIG. 2 , a photoelectric conversion element 100according to the first embodiment of the present disclosure includes asubstrate 102, a lower electrode 104 disposed above the substrate 102,an electron blocking layer 106 disposed above the lower electrode 104, aphotoelectric conversion layer 108 disposed above the electron blockinglayer 106, a hole blocking layer 110 disposed above the photoelectricconversion layer 108, and an upper electrode 112 disposed above the holeblocking layer 110.

However, a structure of the photoelectric conversion element 100illustrated in FIG. 2 is only an example. The structure of thephotoelectric conversion element 100 according to the first embodimentof the present disclosure is not limited to the structure illustrated inFIG. 2 . For example, either or both of the electron blocking layer 106and the hole blocking layer 110 may not be provided.

The substrate 102 is a support in which layers forming the photoelectricconversion element 100 are laminated and disposed. As the substrate 102,a substrate used in a general photoelectric conversion element may beused. For example, the substrate 102 may be various types of glasssubstrates such as a high strain point glass substrate, a soda glasssubstrate and a borosilicate glass substrate, a quartz substrate, asemiconductor substrate, and a plastic substrate such as apolymethylmethacrylate, polyvinyl alcohol, polyimide or polycarbonatesubstrate. In addition, when incident light is transmitted and thetransmitted incident light is received in another photoelectricconversion element again, it is preferable that the substrate 102 bemade of a transparent material.

The lower electrode 104 and the upper electrode 112 are made of aconductive material, and at least one thereof is made of a transparentconductive material. Specifically, the lower electrode 104 and the upperelectrode 112 may be made of indium tin oxide (In₂O₃—SnO₂: ITO), indiumzinc oxide (In₂O₃—ZnO: IZO), and the like. In addition, when incidentlight is transmitted and the transmitted incident light is received inanother photoelectric conversion element again, it is preferable thatthe lower electrode 104 and the upper electrode 112 be made of thetransparent conductive material such as ITO.

Here, a bias voltage is applied to the lower electrode 104 and the upperelectrode 112. For example, the bias voltage is applied to set apolarity such that electrons move to the upper electrode 112 and holesmove to the lower electrode 104 among charges generated in thephotoelectric conversion layer 108.

In addition, it is needless to say that the bias voltage may be appliedto set a polarity such that holes move to the upper electrode 112 andelectrons move to the lower electrode 104 among charges generated in thephotoelectric conversion layer 108. In this case, in the photoelectricconversion element 100 illustrated in FIG. 2 , positions of the electronblocking layer 106 and the hole blocking layer 110 are switched.

The electron blocking layer 106 is a layer that suppresses an increasein a dark current due to introduction of electrons from the lowerelectrode 104 to the photoelectric conversion layer 108 when the biasvoltage is applied. Specifically, the electron blocking layer 106 may bemade of an electron donating material such as arylamine, oxazole,oxadiazole, triazole, imidazole, stilbene, a polyarylalkane, porphyrin,anthracene, fluorenone and hydrazine. For example, the electron blockinglayer 106 may be made ofN,N′-bis(3-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TPD),N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (alpha-NPD),4,4′,4″-tris(N-(3-methylphenyl)N-phenylamino) triphenylamine (m-MTDATA),tetraphenylporphyrin copper, phthalocyanine, or copper phthalocyanine.

The photoelectric conversion layer 108 is a layer that selectivelyabsorbs light of a specific wavelength and performs photoelectricconversion on the absorbed light. Specifically, the photoelectricconversion layer 108 is formed of the photoelectric conversion film thathas been described in the above (2.1. Configuration of photoelectricconversion film according to first embodiment). Accordingly, thephotoelectric conversion layer 108 can selectively absorb green light(for example, light having a wavelength of greater than or equal to 450nm and less than 600 nm).

The hole blocking layer 110 is a layer that suppresses an increase in adark current due to introduction of holes from the upper electrode 112to the photoelectric conversion layer 108 when the bias voltage isapplied. Specifically, the hole blocking layer 110 may be made of anelectron accepting material such as a fullerene, carbon nanotubes,oxadiazole, a triazole compound, anthraquinodimethane, diphenylquinone,distyrylarylene, and a silole compound. For example, the hole blockinglayer 110 may be made of1,3-bis(4-tert-butylphenyl-1,3,4-oxadiazolyl)phenylene (OXD-7),bathocuproine, bathophenanthroline, ortris(8-hydroxyquinolinato)aluminum (Alq3).

In addition, in the structure of the photoelectric conversion element100 illustrated in FIG. 2 , materials forming layers other than thephotoelectric conversion layer 108 are not specifically limited, but aknown material for the photoelectric conversion element may also beused.

Here, each of the layers in the photoelectric conversion element 100according to the first embodiment of the present disclosure describedabove may be formed by an appropriate film formation method that isselected according to a material such as a deposition method, asputtering method, and various coating methods.

For example, in each of the layers forming the photoelectric conversionelement 100 according to the first embodiment of the present disclosure,the lower electrode 104 and the upper electrode 112 may be formed by adeposition method including an electron beam deposition method, a hotfilament deposition method and a vacuum deposition method, a sputteringmethod, a chemical vapor deposition method (CVD method), a combinationof an ion plating method and an etching method, various types ofprinting methods such as a screen printing method, an ink jet printingmethod and a metal mask printing method, a plating method (anelectroplating method and an electroless plating method), and the like.

In addition, in each of the layers forming the photoelectric conversionelement 100 according to the first embodiment of the present disclosure,an organic layer such as the electron blocking layer 106, thephotoelectric conversion layer 108 and the hole blocking layer 110 maybe formed by, for example, the deposition method such as the vacuumdeposition method, the printing method such as the screen printingmethod and the ink jet printing method, a laser transfer method or thecoating method such as a spin coating method.

An exemplary configuration of the photoelectric conversion element 100according to the first embodiment of the present disclosure has beendescribed above.

2.3. Example According to First Embodiment

Hereinafter, the photoelectric conversion film and the photoelectricconversion element according to the first embodiment of the presentdisclosure will be described in detail with reference to examples andcomparative examples. However, the following examples are only examplesand the photoelectric conversion film and the photoelectric conversionelement according to the first embodiment of the present disclosure arenot limited to the following examples.

(Simulation Analysis)

First, spectral characteristics of the subphthalocyanine derivativeaccording to the first embodiment of the present disclosure wereevaluated by simulation analysis. Specifically, the simulation analysiswas performed on the subphthalocyanine derivative represented by thefollowing structural formula and HOMO and LUMO levels and a maximumabsorption wavelength lambda_(max), were calculated.

Here, “F6-SubPc-Cl,” “F3(C3)-SubPc-Cl,” and “F3(C1)-SubPc-Cl” are thesubphthalocyanine derivatives according to the first embodiment of thepresent disclosure (Examples 1 to 3). “Bay-F6-SubPc-Cl,” “F12-SubPc-Cl,”“C16-SubPc-Cl,” “BayC16-SubPc-Cl,” and “C112-SubPc-Cl” aresubphthalocyanine derivatives (Comparative examples 1 to 5) that are notincluded in the first embodiment of the present disclosure.

In addition, in the simulation analysis, calculation was performedaccording to a density functional theory (DFT), and Gaussian 09 was usedas a calculation program and calculated at the level of“B3LYP/6-31+G**”.

The HOMO and LUMO levels and the maximum absorption wavelengthlambda_(max) of each of the subphthalocyanine derivatives that werecomputed by the simulation analysis are shown in Table 1. In addition,since the HOMO and LUMO levels and the maximum absorption wavelengthlambda_(max) of the subphthalocyanine derivatives shown in Table 1 aresimulation analysis results in a single molecule, an absolute value doesnot strictly match an actual measured value in a thin film to bedescribed.

TABLE 1 HOMO LUMO (eV) (eV) λ_(max) (nm) Example 1 F6-SubPc—Cl −6.18−3.44 492.76 Example 2 F3-C1-SubPc—Cl −5.89 −3.19 497.38 Example 3F3-C3-SubPc—Cl −5.89 −3.22 491.27 Comparative Bay-F6-SubPc—Cl −5.99−3.14 520.39 example 1 Comparative F12-SubPc—Cl −6.51 −3.9 513.96example 2 Comparative Cl6-SubPc—Cl −6.15 −3.49 510.02 example 3Comparative Bay-Cl6-SubPc—Cl −5.98 −3.39 525.73 example 4 ComparativeCl12-SubPc—Cl −6.33 −3.76 533.21 example 5

As shown in Table 1, it can be understood that the subphthalocyaninederivatives according to Examples 1 to 3 have a shorter maximumabsorption wavelength lambda_(max) than the subphthalocyaninederivatives according to Comparative examples 1 to 5.

Specifically, in the subphthalocyanine derivatives according to Examples1 to 3, at least any one beta position (R₁₁ to R₁₆) of asubphthalocyanine skeleton is substituted with fluorine. Therefore, themaximum absorption wavelength lambda_(max) becomes a shorter wavelength.In addition, in the subphthalocyanine derivative according to Example 1,it can be understood that, since all beta positions (R₁₁ to R₁₆) of thesubphthalocyanine skeleton are substituted with fluorine, the maximumabsorption wavelength lambda_(max) becomes a shorter wavelength thanthose of the subphthalocyanine derivatives according to Examples 2 and 3in which beta positions are partially substituted with fluorine.

On the other hand, in the subphthalocyanine derivatives according toComparative examples 1 and 2, since an alpha position of thesubphthalocyanine skeleton is substituted with fluorine, the maximumabsorption wavelength lambda_(max) becomes longer compared to thesubphthalocyanine derivatives according to Examples 1 to 3. In addition,in the subphthalocyanine derivative according to Comparative example 2,all beta positions (R₁₁ to R₁₆) of the subphthalocyanine skeleton aresubstituted with fluorine, but the alpha position is also substitutedwith fluorine. Therefore, compared to the subphthalocyanine derivativesaccording to Examples 1 to 3, the maximum absorption wavelengthlambda_(max) becomes longer.

A change in spectral characteristics according to a position of such asubstituent is considered to be caused by molecular orbitals of the HOMOlevel and the LUMO level that influence spectral characteristics ofsubphthalocyanine being present at the alpha position and the betaposition of the subphthalocyanine skeleton. Accordingly, in thesubphthalocyanine derivative according to the first embodiment of thepresent disclosure, it is considered to be important that all alphapositions be hydrogen and at least any one beta position (R₁₁ to R₁₆) besubstituted with fluorine in the subphthalocyanine skeleton.

In addition, in the subphthalocyanine derivatives according toComparative examples 3 to 5, the alpha position or the beta position ofthe subphthalocyanine skeleton is substituted with chlorine. Therefore,compared to the subphthalocyanine derivatives according to Examples 1 to3, the maximum absorption wavelength lambda_(m)ax becomes longer.Accordingly, in the subphthalocyanine derivative according to the firstembodiment of the present disclosure, it is considered to be importantthat a substituent for substituting the subphthalocyanine skeleton befluorine.

(Synthesis of Subphthalocyanine Derivative)

Next, a synthesizing method of the subphthalocyanine derivativeaccording to the first embodiment of the present disclosure will bedescribed. Specifically, the above-described compound 2 (F6-SubPc-Cl)and compound 9 (F6-SubPc-OC6F5) were synthesized by the followingsynthesizing method. The synthesized subphthalocyanine derivatives wereidentified using nuclear magnetic resonance (¹HNMR) and field desorptionmassspectrometry (FD-MS). However, the synthesizing method to bedescribed below is only an example, and the synthesizing method of thesubphthalocyanine derivative according to the first embodiment of thepresent disclosure is not limited to the following example.

Synthesis of F6-SubPc-Cl

F6-SubPc-Cl serving as the subphthalocyanine derivative according to thefirst embodiment of the present disclosure was synthesized through thefollowing Reaction formula 1.

Difluorophthalonitrile (30 g, 183 mmol) was added to 1-chloronaphthalene(150 ml) in which BCl₃ (14 g, 120 mmol) was dissolved, and the mixturewas heated to reflux under a nitrogen atmosphere. After cooling, themixture was separated and purified by silica chromatography, and then aproduct was purified by sublimation and purification to obtainF6-SubPc-Cl (11 g, yield 34%).

Synthesis of F6-SubPc-OC6F5

F6-SubPc-OC6F5 serving as the subphthalocyanine derivative according tothe first embodiment of the present disclosure was synthesized throughthe following Reaction formula 2.

Pentafluorophenol (13 g, 10 mmol) was added to chlorobenzene (100 ml) inwhich F6-SubPc-Cl (10 g, 2.3 mmol) that was synthesized by the abovesynthesizing method was dissolved, and the mixture was heated to reflux.After cooling, the mixture was separated and purified by silicachromatography, and then a product was purified by sublimation andpurification to obtain F6-SubPc-OC6F5 (5.9 g, yield 60%).

(Evaluation of Spectral Characteristics)

Subsequently, spectral characteristics of the subphthalocyaninederivative according to the first embodiment of the present disclosurewere evaluated. Specifically, an evaluation sample including thesubphthalocyanine derivative according to the first embodiment of thepresent disclosure was manufactured, and a change in spectralcharacteristics was measured before and after annealing.

Example 4

First, a glass substrate with an ITO electrode was washed by UV/ozonetreatment. In addition, a film thickness of an ITO film in the glasssubstrate was 50 nm. Next, the glass substrate was put into an organicdeposition apparatus and the synthesized F6-SubPc-Cl was deposited at adeposition rate of 0.1 nm/sec by a resistance heating method whilerotating a substrate holder in a vacuum of less than or equal to 1×10⁻⁵Pa. A film thickness of the deposited F6-SubPc-Cl was 50 nm. Further, inorder to cover the organic layer, the ITO film was formed at a filmthickness of 50 nm by the sputtering method to manufacture a spectralcharacteristic evaluation sample.

Comparative Example 6

A spectral characteristic evaluation sample was manufactured by the samemethod as in Example 4 except that F12-SubPc-Cl to be described in thefollowing synthesizing method was used instead of F6-SubPc-Cl used inExample 4.

Also, F12-SubPc-Cl used in Comparative example 6 was synthesized by thefollowing reaction formula 3. In addition, the synthesized F12-SubPc-Clwas identified using NMR and FD-MS.

Tetrafluorophthalonitrile (37 g, 183 mmol) was added to1-chloronaphthalene (150 ml) in which BCl₃ (14 g, 120 mmol) wasdissolved, and the mixture was heated to reflux under a nitrogenatmosphere. After cooling, the mixture was separated and purified bysilica chromatography, and then a product was purified by sublimationand purification to obtain F12-SubPc-Cl (5.3 g, yield 64%).

Comparative Example 7

A spectral characteristic evaluation sample was manufactured by the samemethod as in Example 4 except that SubPc-OC6F5 to be described in thefollowing synthesizing method was used instead of F6-SubPc-Cl used inExample 4.

Also, SubPc-OC6F5 used in Comparative example 7 was synthesized by thefollowing reaction formula 4. In addition, the synthesized SubPc-OC6F5was identified using NMR and FD-MS.

Pentafluorophenol (13 g, 10 mmol) was added to 1,2-chlorobenzene (100ml) in which the sublimated and purified subphthalocyanine (manufacturedby Tokyo Chemical Industry Co., Ltd.) (10 g, 2.3 mmol) was dissolved,and the mixture was heated to reflux. After cooling, the mixture wasseparated and purified by silica column chromatography, and then aproduct was purified by sublimation and purification to obtainSubPc-OC6F5 (6.5 g, yield 65%).

Comparative Example 8

A spectral characteristic evaluation sample was manufactured by the samemethod as in Example 4 except that subphthalocyanine chloride (SubPc-Cl)represented by the following structural formula was used instead ofF6-SubPc-Cl used in Example 4. In addition, as the subphthalocyaninechloride, a sublimated and purified product purchased from TokyoChemical Industry Co., Ltd. was used.

Reference Example

A spectral characteristic evaluation sample was manufactured by the samemethod as in Example 4 except that quinacridone (QD) represented by thefollowing structural formula was used instead of F6-SubPc-Cl used inExample 4. In addition, as the quinacridone, a sublimated and purifiedproduct purchased from Tokyo Chemical Industry Co., Ltd. was used.

A change in spectral characteristics before and after annealing wasevaluated for the manufactured spectral characteristic evaluationsamples of Example 4, Comparative examples 7 to 9 and the referenceexample using an ultraviolet and visible spectrophotometer.Specifically, before annealing, after annealing for 60 minutes at 160degrees Celsius and after annealing for 210 minutes at 160 degreesCelsius, spectral characteristics of Example 4, Comparative examples 7to 9 and the reference example were measured. The evaluation results ofchanges in spectral characteristics are shown in FIGS. 3A to 3E.

Here, FIG. 3A shows the graph of evaluation results of a change inspectral characteristics of Example 4 (F6-SubPc-Cl). In addition, FIG.3B shows the graph of evaluation results of a change in spectralcharacteristics of Comparative example 7 (F12-SubPc-Cl). FIG. 3C showsthe graph of evaluation results of a change in spectral characteristicsof Comparative example 8 (SubPc-OC6F5). FIG. 3D shows the graph ofevaluation results of a change in spectral characteristics ofComparative example 9 (SubPc-Cl). In addition, FIG. 3E shows the graphof evaluation results of a change in spectral characteristics of thereference example (QD).

Referring to FIG. 3A, it can be understood in Example 4 that absorptionof red light having a wavelength of greater than or equal to 600 nm islow and green light can be selectively absorbed. In addition, it can beunderstood in Example 4 that an absorption coefficient had almost nochange before and after annealing and a heat resistance was high.

On the other hand, as shown in FIGS. 3C to 3E, it can be understood inComparative example 7 (F12-SubPc-Cl), Comparative example 8(SubPc-OC6F5) and Comparative example 9 (SubPc-Cl) that absorption of awavelength of greater than or equal to 600 nm is high and red light isabsorbed. In addition, it can be understood in Comparative examples 7 to9 that an absorption coefficient is significantly changed both beforeand after annealing and a heat resistance is also low.

Further, it can be understood that Example 4 had spectralcharacteristics similar to spectral characteristics of the referenceexample (quinacridone) shown in FIG. 3E. Accordingly, it can beunderstood that, when the subphthalocyanine derivative according to thefirst embodiment of the present disclosure forms the bulk hetero mixedfilm with the quinacridone derivative, a wavelength band of light to beabsorbed does not become wider and it is possible to form thephotoelectric conversion film having a sharp absorption peak in thegreen band.

Based on the above results, it can be understood that, since thesubphthalocyanine derivative according to the first embodiment of thepresent disclosure can selectively absorb green light, it is appropriatefor a material of a green photoelectric conversion film of thesolid-state image sensor.

(Evaluation of Photoelectric Conversion Element)

In addition, the photoelectric conversion element according to the firstembodiment of the present disclosure was manufactured by the followingmanufacturing methods. However, structures and manufacturing methods ofphotoelectric conversion elements to be described below are onlyexamples. The structure and the manufacturing method of thephotoelectric conversion element according to the first embodiment ofthe present disclosure are not limited to the following examples.

Here, in the following examples, F6-SubPc-Cl, F6-SubPc-OC6F5,F12-SubPc-Cl and SubPc-OC6F5 were synthesized, sublimated and purifiedby the above-described method, and used. In addition, as SubPc-Cl,quinacridone and N,N′-dimethylquinacridone, sublimated and purifiedproducts purchased from Tokyo Chemical Industry Co., Ltd. were used.

Example 5

First, a glass substrate with an ITO electrode was washed by UV/ozonetreatment. In addition, a film thickness of an ITO film corresponding toa lower electrode in the glass substrate was 50 nm. Next, the glasssubstrate was put into an organic deposition apparatus, a pressure wasdecreased to less than or equal to 1×10−5 Pa, and F6-SubPc-Cl andquinacridone were deposited by a resistance heating method whilerotating a substrate holder. In addition, deposition was performed at adeposition rate of 0.1 nm/sec such that a ratio of F6-SubPc-Cl andquinacridone became 1:1, and a film of 100 nm in total was formed toform the photoelectric conversion layer.

Further, a film of AlSiCu was formed above the photoelectric conversionlayer at a film thickness of 100 nm by the deposition method to form anupper electrode. By the above manufacturing method, the photoelectricconversion element including a photoelectric conversion area of 1 mm×1mm was manufactured.

Example 6

A photoelectric conversion element was manufactured by the same methodas in Example 5 except that F6-SubPc-OC6F5 was used instead ofF6-SubPc-Cl used in Example 5.

Example 7

A photoelectric conversion element was manufactured by the same methodas in Example 5 except that N,N′-dimethylquinacridone (DMQD) representedby the following structural formula was used instead of quinacridoneused in Example 5.

Comparative Example 10

A photoelectric conversion element was manufactured by the same methodas in Example 5 except that SubPc-Cl was used instead of F6-SubPc-Clused in Example 5.

Comparative Example 11

A photoelectric conversion element was manufactured by the same methodas in Example 5 except that SubPc-OC6F5 was used instead of F6-SubPc-Clused in Example 5.

Comparative Example 12

A photoelectric conversion element was manufactured by the same methodas in Example 5 except that F12-SubPc-Cl was used instead of F6-SubPc-Clused in Example 5.

Comparative Example 13

A photoelectric conversion element was manufactured by the same methodas in Example 5 except that N, N′-dimethylquinacridone and SubPc-Cl wereused instead of quinacridone and F6-SubPc-Cl used in Example 5.

Comparative Example 14

A photoelectric conversion element was manufactured by the same methodas in Example 5 except that N, N′-dimethylquinacridone and SubPc-OC6F5were used instead of quinacridone and F6-SubPc-Cl used in Example 5.

Comparative Example 15

A photoelectric conversion element was manufactured by the same methodas in Example 5 except that SubPc-Cl was used instead of quinacridoneused in Example 5.

(Evaluation Result)

First, photoelectric conversion efficiency and spectral characteristicswere evaluated for the photoelectric conversion elements according toExamples 5 to 7 and Comparative examples 10 to 15 manufactured asdescribed above.

Photoelectric conversion efficiency was evaluated by measuring externalquantum efficiency using a semiconductor parameter analyzer.Specifically, light having an intensity of 1.62 microwatts per squarecentimeter was radiated to the photoelectric conversion element from alight source through a filter, and external quantum efficiency wascomputed from a light current value and a dark current value when thebias voltage applied between electrodes was set to −1 V. Such externalquantum efficiency was measured before and after annealing for 210minutes at 160 degrees Celsius, and external quantum efficiency afterannealing was divided by external quantum efficiency before annealing tocompute an annealing resistance.

In addition, spectral characteristics were evaluated using theultraviolet and visible spectrophotometer. An absorption coefficient at600 nm was divided by an absorption coefficient at a maximum absorptionwavelength lambda_(max), to compute an absorption rate at 600 nm.

The results of the above evaluation are shown in the following Table 2.In Table 2, “QD” represents quinacridone, and “DMQD” representsN,N′-dimethylquinacridone.

TABLE 2 External quantum efficiency Spectral Photoelectric Before AfterAnnealing characteristics conversion annealing annealing resistance 600nm/λ_(max) layer (%) (%) (%) (%) Example 5 QD:F6-SubPc—Cl 66 68 103 20Example 6 QD:F6-SubPc-OC6F5 72 68 94 18 Example 7 DMQD:F6-SubPc—Cl 43 4298 25 Comparative QD:SubPc—Cl 45 44 98 45 example 10 ComparativeQD:SubPc-OC6F5 56 23 41 44 example 11 Comparative QD:F12-SubPc—Cl 64 4063 60 example 12 Comparative DMQD:SubPc—Cl 36 24 67 54 example 13Comparative DMQD:SubPc-OC6F5 52 28 54 52 example 14 ComparativeSubPc—Cl:F6-SubPc—Cl 13 11 85 71 example 15

As shown in the results in Table 2, it can be understood that Examples 5to 7 including the photoelectric conversion element according to thefirst embodiment of the present disclosure have a lower absorption rateat 600 nm and a higher annealing resistance than Comparative examples 10to 15. In addition, it can be understood that Examples 5 to 7 have agenerally higher external quantum efficiency after annealing thanComparative examples 10 to 15.

Specifically, it can be understood that Examples 5 to 7 include thesubphthalocyanine derivative and the quinacridone derivative accordingto the first embodiment of the present disclosure and therefore have alower absorption rate at 600 nm and a higher annealing resistance thanComparative examples 11 to 15. In addition, since Comparative example 10has a high annealing resistance but an absorption rate at 600 nm ishigh, it is not preferable.

Subsequently, in Examples 5 to 7 and Comparative examples 10 to 15, HOMOlevels and LUMO levels of the subphthalocyanine derivative and thequinacridone derivative used in the photoelectric conversion layer weremeasured.

In addition, in order to measure the HOMO level, a sample in which eachorganic material was formed into a 20 nm film by the deposition methodon a silicon substrate that had been treated with UV/ozone was used. TheHOMO level was computed for the sample in which each organic materialwas formed into a film using an ultraviolet photoelectron spectroscopy(UPS) method.

In addition, in order to measure the LUMO level, a sample in which eachorganic material was formed into a 50 nm film by the deposition methodon a quartz substrate that had been treated with UV/ozone was used.First, a transmittance and a reflectance of the sample were measured bya spectrophotometer (JASCO V-570), and an absorption coefficient alphawith respect to a wavelength was computed. Next, an absorption end of avisible light area of the computed absorption coefficient alpha wascomputed as an HOMO-LUMO gap, and the HOMO-LUMO gap was subtracted fromthe HOMO level to compute the LUMO level.

The measured HOMO levels, LUMO levels and maximum absorption wavelengthslambda_(max) of the subphthalocyanine derivatives and the quinacridonederivatives are shown in the following Table 3. In Table 3, “QD”represents quinacridone, and “DMQD” representsN,N′-dimethylquinacridone.

TABLE 3 HOMO LUMO (eV) (eV) λ_(max) (nm) F6-SubPc—Cl −6.3 −4.2 566SubPc—Cl −5.7 −3.7 587 SubPc-OC6F5 −5.7 −3.7 577 F12-SubPc—Cl −6.6 −4.6584 QD −5.55 −3.55 561 DMQD −5.5 −3.3 532

As shown in the results in Table 3, it can be understood that“F6-SubPc-Cl” serving as the subphthalocyanine derivative according tothe first embodiment of the present disclosure has a shorter maximumabsorption wavelength lambda_(max) even in a thin film than “SubPc-Cl,”“SubPc-OC6F5,” and “F12-SubPc-Cl” serving as the subphthalocyaninederivative according to the comparative example.

In addition, it can be understood that, in “F6-SubPc-Cl” serving as thesubphthalocyanine derivative according to the first embodiment of thepresent disclosure, an LUMO level difference between “QD” and “DMQD”that form the bulk hetero mixed film in Example 5 or 7 is included in apreferable range (greater than or equal to 0.1 eV and less than or equalto 1.0 eV) in the first embodiment of the present disclosure.

As can be understood from the above results, when the photoelectricconversion film according to the first embodiment of the presentdisclosure includes the quinacridone derivative represented by Generalformula (1) and the subphthalocyanine derivative represented by Generalformula (2), it is possible to increase a heat resistance andselectively absorb green light. Accordingly, since the photoelectricconversion film according to the first embodiment of the presentdisclosure can be appropriately used as the green photoelectricconversion film in the solid-state image sensor, it is possible toincrease sensitivity of the solid-state image sensor.

3. SECOND EMBODIMENT 3.1. Configuration of Photoelectric Conversion FilmAccording to Second Embodiment

Next, the photoelectric conversion film according to the secondembodiment of the present disclosure will be described. Thephotoelectric conversion film according to the second embodiment of thepresent disclosure is a photoelectric conversion film including atransparent compound that is represented by the following Generalformula (3) or (4) and does not absorb visible light.

In General Formula (3) above, R₂₁ to R₃₂ each independently representany substituent selected from the group consisting of hydrogen, ahalogen, a hydroxy group, an alkoxy group, a cyano group, a nitro group,a silylalkyl group, a silylalkoxy group, an arylsilyl group, a thioalkylgroup, a thioaryl group, a sulfonyl group, an arylsulfonyl group, analkylsulfonyl group, an amino group, an alkylamino group, an arylaminogroup, an acyl group, an acylamino group, an acyloxy group, a carboxygroup, a carboxamido group, a carboalkoxy group, a substituted orunsubstituted alkyl group, a substituted or unsubstituted cycloalkylgroup, a substituted or unsubstituted aryl group, and a substituted orunsubstituted heteroaryl group, or an aryl or heteroaryl group formed bycondensing at least two or more of any adjacent R₂₁ to R₃₂.

In General Formula (4) above, R₄₁ to R₄₈ each independently representany substituent selected from the group consisting of hydrogen, ahalogen, a hydroxy group, an alkoxy group, a cyano group, a nitro group,a silylalkyl group, a silylalkoxy group, an arylsilyl group, a thioalkylgroup, a thioaryl group, a sulfonyl group, an arylsulfonyl group, analkylsulfonyl group, an amino group, an alkylamino group, an arylaminogroup, an acyl group, an acylamino group, an acyloxy group, an imidegroup, a carboxy group, a carboxamido group, a carboalkoxy group, asubstituted or unsubstituted alkyl group, a substituted or unsubstitutedcycloalkyl group, a substituted or unsubstituted aryl group, and asubstituted or unsubstituted heteroaryl group, or an aryl or heteroarylgroup formed by condensing at least two or more of any adjacent R₄₁ toR₄₈, and Ar₁ to Ar₄ each independently represent a substituted orunsubstituted aryl group or a substituted or unsubstituted heteroarylgroup.

Here, the photoelectric conversion film according to the secondembodiment of the present disclosure may further include an organic dyecompound and may be formed as the bulk hetero mixed film similar to thefirst embodiment. In this case, for example, since the organic dyecompound serves as the p type photoelectric conversion material and thetransparent compound represented by General formula (3) or (4) serves asthe n type photoelectric conversion material, a bulk heterojunction isformed therebetween.

Here, as described in the first embodiment of the present disclosure, inthe bulk hetero mixed film, spectral characteristics are influenced byboth spectral characteristics of the p type photoelectric conversionmaterial and the n type photoelectric conversion material to be mixed.Accordingly, when spectral characteristics of the p type photoelectricconversion material and the n type photoelectric conversion material donot match, the photoelectric conversion film formed as the bulk heteromixed film has a wide wavelength band of light to be absorbed, andappropriate spectral characteristics as the photoelectric conversionfilm in the solid-state image sensor may not be obtained.

In the photoelectric conversion film according to the second embodimentof the present disclosure, when the transparent compound that is atransparent compound that does not absorb visible light and isrepresented by General formula (3) or (4) is used, it is possible toprevent a wavelength band of light to be absorbed in the photoelectricconversion film from becoming wider. Specifically, in the photoelectricconversion film according to the second embodiment of the presentdisclosure, since the transparent compound represented by Generalformula (3) or (4) does not absorb visible light, it is possible to havespectral characteristics in which spectral characteristics of theorganic dye compound to be included are reflected.

As the organic dye compound included in the photoelectric conversionfilm according to the second embodiment of the present disclosure,anything can be used. For example, as the organic dye compound, cyaninedyes, styryl dyes, hemicyanine dyes, merocyanine dyes (includeszeromethinemerocyanine and simple merocyanine), trinuclear merocyaninedyes, tetranuclear merocyanine dyes, rhodacyanine dyes, complex cyaninedyes, complex merocyanine dyes, allopolar dyes, oxonol dyes, hemi oxonoldyes, squalium dyes, croconium dyes, azamethine dyes, coumarin dyes,arylidene dyes, anthraquinone dyes, triphenylmethane dyes, azo dyes,azomethine dyes, spiro compounds, metallocene dyes, fluorenone dyes,fulgide dyes, perylene dyes, perynone dyes, phenazine dyes,phenothiazine dyes, quinone dyes, diphenylmethane dyes, polyene dyes,acridine dyes, acridinone dyes, diphenylamine dyes, quinacridone dyes,quinophthalone dyes, phenoxazine dyes, phthaloperylene dyes,diketopyrrolopyrrole dyes, dioxane dyes, porphyrin dyes, chlorophylldyes, phthalocyanine dyes, metal complex dyes, or condensed aromaticcarbocyclic system dyes (such as naphthalene derivatives, anthracenederivatives, phenanthrene derivatives, tetracene derivatives, pyrenederivatives, perylene derivatives and fluoranthene derivatives) arepreferably used. In addition, in the second embodiment of the presentdisclosure, as the organic dye compound, the quinacridone derivative ismore preferably used.

For example, when the photoelectric conversion film according to thesecond embodiment of the present disclosure includes the quinacridonederivative represented by General formula (1), it is possible to havespectral characteristics in which spectral characteristics of thequinacridone derivative represented by General formula (1) arereflected. In this case, since the photoelectric conversion filmaccording to the second embodiment of the present disclosure canselectively absorb green light similar to the quinacridone derivativerepresented by General formula (1), it is possible to implementappropriate spectral characteristics as the photoelectric conversionfilm of green light in the solid-state image sensor.

In addition, the transparent compound represented by General formula (3)or (4) can form a bulk hetero mixed layer that includes crystal fineparticles of sizes that are appropriate for charge separation with thequinacridone derivative represented by General formula (1). Accordingly,in the photoelectric conversion film according to the second embodimentof the present disclosure, charge separation of excitons generated whenthe quinacridone derivative absorbs light can be quickly performed ateach interface. In particular, since the transparent compoundrepresented by General formula (3) or (4) has an electron acceptingability and has a high electron mobility, charge separation is performedon the bulk hetero mixed film with high efficiency, and photoelectricconversion efficiency of the photoelectric conversion film can beincreased.

In the photoelectric conversion film according to the second embodimentof the present disclosure, a mixing ratio of the transparent compoundrepresented by General formula (3) or (4) and the organic dye compoundmay be any ratio, but, for example, transparent compound:organic dyecompound=10:90 to 90:10 (volume ratio) is preferable, and 20:80 to 50:50(volume ratio) is more preferable. On the other hand, when an absoluteamount of the organic dye compound included in the photoelectricconversion film is too small, since there is a possibility ofinsufficient absorption of incident light by the dye, it is notpreferable. In addition, when an absolute amount of the transparentcompound included in the photoelectric conversion film is too small,since a conductive path between the transparent compound and the organicdye compound that is necessary for generated carriers (that is,electrons and holes) to move to corresponding electrodes smoothly is notformed, it is not preferable.

Here, in General formula (3), R₂₁ to R₃₂ are hydrogen or anysubstituent, and preferably, all of R₂₁, R₂₄, R₂₅, R₂₈, R₂₉, and R₃₂ maybe hydrogen.

For example, as a specific example of the transparent compoundrepresented by General formula (3), a compound represented by thefollowing structural formula can be exemplified. However, thetransparent compound represented by General formula (3) according to thesecond embodiment of the present disclosure is not limited to thefollowing exemplary compounds.

In addition, in General formula (4), R₄₁ to R₄₈ each independentlyrepresent hydrogen or any substituent, and Ar₁ to Ar₄ each independentlyrepresent a substituted or unsubstituted aryl group or a substituted orunsubstituted heteroaryl group.

As an aryl group that can be obtained by Ar₁ to Ar₄, a phenyl group, abiphenyl group, a terphenyl group, a naphthyl group, an anthryl group, aphenanthrenyl group, a fluorenyl group, and an indenyl group areexemplified. In addition, as a heteroaryl group that can be obtained byAr₁ to Ar₄, a thienyl group, a furanyl group, a pyrrolyl group, athiazolyl group, a thiadiazolyl group, an imidazolyl group, an oxazolylgroup, an oxadiazolyl group, a pyridinyl group and a pyrimidinyl groupare exemplified.

In addition, Ar₁ to Ar₄ may be an aryl or heteroaryl group having asubstituent. As the substituent of Ar₁ to Ar₄, a halogen, a hydroxygroup, an alkoxy group, a cyano group, a nitro group, a silylalkylgroup, a silylalkoxy group, an arylsilyl group, a thioalkyl group, athioaryl group, a sulfonyl group, an arylsulfonyl group, analkylsulfonyl group, an amino group, an alkylamino group, an arylaminogroup, an acyl group, an acylamino group, an acyloxy group, a carboxygroup, a carboxamido group and a carboalkoxy group are exemplified.

In General formula (4), it is preferable that at least one ofsubstituents of Ar₁ to Ar₄ and R₄₁ to R_(4U) be an electron attractinggroup. In other words, the transparent compound represented by Generalformula (4) has preferably at least one electron attracting group as thesubstituent. In this case, in the transparent compound represented byGeneral formula (4), since the LUMO level becomes deeper (an absolutevalue increases) and becomes an LUMO level at which charge separationfrom the organic dye compound can be efficiently performed, it ispossible to increase photoelectric conversion efficiency.

In addition, in order to set the LUMO level of the transparent compoundrepresented by General formula (4) to a more appropriate value, it ispreferable that the transparent compound represented by General formula(4) include more electron attracting groups, and it is preferable thatthe substituent to be included have a higher electron withdrawingability. Further, when Ar₁ to Ar₄ include an electron attracting groupas the substituent, a substitution position of the electron attractinggroup is preferably a position of a para position with respect tobinding positions of Ar₁ to Ar₄ and a triazine ring. In this case, sincethe transparent compound represented by General formula (4) has an LUMOlevel at which charge separation from the organic dye compound can bemore efficiently performed, it is possible to increase photoelectricconversion efficiency of the photoelectric conversion film.

In the above description, the electron attracting group may be, forexample, a halogen, a cyano group, a nitro group, a sulfonyl group, anarylsulfonyl group, an alkylsulfonyl group, an acyl group, an acylaminogroup, an acyloxy group, an imide group, a carboxy group, a carboxamidogroup, a carboalkoxy group, a halogenated alkyl group, and a halogenatedaryl group.

As a preferable specific example of the transparent compound representedby General formula (4), a compound represented by the followingstructural formula can be exemplified. However, the transparent compoundrepresented by General formula (4) according to the second embodiment ofthe present disclosure is not limited to the following exemplarycompounds. In addition, referring to the following exemplary compounds,it can be understood that, when Ar₁ to Ar₄ are a heteroaryl groupserving as an electron donor, R₄₁ to R₄₈ are preferably an electronattracting group serving as an electron acceptor.

In addition, HOMO and LUMO levels of the transparent compoundrepresented by General formula (3) or (4) are preferably levels at whichthe photoelectric conversion mechanism can be smoothly performed on theorganic dye compound.

Specifically, in order for the transparent compound represented byGeneral formula (3) or (4) to serve as the n type photoelectricconversion material and the organic dye compound to serve as the p typephotoelectric conversion material, it is preferable that the LUMO levelof the transparent compound represented by General formula (3) or (4) belower than the LUMO level of the organic dye compound.

Here, as the photoelectric conversion mechanism in the photoelectricconversion film according to the second embodiment of the presentdisclosure, the following mechanism is specifically considered. That is,when the organic dye compound serving as the p type photoelectricconversion material absorbs light to excite and excited electrons moveto the transparent compound that serves as the n type photoelectricconversion material and is represented by General formula (3) or (4),charge separation is performed. In this case, the LUMO level of thetransparent compound represented by General formula (3) or (4) ispreferably a level at which excited electrons in the organic dyecompound can move to the transparent compound represented by Generalformula (3) or (4) smoothly.

Specifically, it is preferable that a difference between the LUMO levelof the transparent compound represented by General formula (3) or (4)and the LUMO level of the organic dye compound represented by Generalformula (1) be greater than or equal to 0.1 eV and less than or equal to1.0 eV.

For example, when the quinacridone derivative represented by thefollowing General formula (1) is used as the organic dye compound, inconsideration of the LUMO level of the quinacridone derivative, the LUMOlevel of the transparent compound represented by General formula (3) or(4) is preferably greater than or equal to −4.8 eV and less than orequal to −3.5 eV, and more preferably, greater than or equal to −4.5 eVand less than or equal to −3.8 eV.

In addition, the HOMO level of the transparent compound represented byGeneral formula (3) or (4) is preferably, for example, greater than orequal to −7.8 eV and less than or equal to −6.5 eV, and more preferably,greater than or equal to −7.5 eV and less than or equal to −6.8 eV.

Here, as a compound having the same hexaazatriphenylene skeleton as thetransparent compound represented by General formula (3), for example,hexaazatriphenylene-hexacarbonitrile (HAT-CN) represented by thefollowing structural formula can be exemplified.

HAT-CN is, for example, a compound that is used as a charge transportmaterial in an organic electroluminescence element. However, sinceHAT-CN has an LUMO level of about −5.58 eV, it has a great differencefrom the LUMO level of the organic dye compound forming the bulk heteromixed film in the photoelectric conversion film. Accordingly, in thephotoelectric conversion film, when HAT-CN is used as the n typephotoelectric conversion material, it is difficult to move excitedelectrons smoothly at an interface between HAT-CN and the organic dyecompound.

Therefore, in the transparent compound included in the photoelectricconversion film according to the second embodiment of the presentdisclosure, among compounds having a structure represented by Generalformula (3) or (4), a compound having an LUMO level that is relativelyclose to that of the organic dye compound forming the bulk hetero mixedfilm is preferable. Specifically, it is preferable that the transparentcompound represented by General formula (3) or (4) have a structure thathas a difference of greater than or equal to 0.1 eV and less than orequal to 1.0 eV of the LUMO level from the organic dye compound.

As described above, when the photoelectric conversion film according tothe second embodiment of the present disclosure includes the organic dyecompound and the transparent compound represented by General formula (3)or (4), it is possible to selectively perform photoelectric conversionon light that is absorbed by the organic dye compound. For example, whenthe quinacridone derivative represented by General formula (1) is usedas the organic dye compound, the photoelectric conversion film accordingto the second embodiment of the present disclosure can selectivelyperform photoelectric conversion on green light (for example, lighthaving a wavelength of greater than or equal to 450 nm and less than 600nm).

In addition, since the transparent compound represented by Generalformula (3) or (4) has a high electron mobility and can form the bulkhetero mixed film with the organic dye compound with high chargeseparation efficiency, it is possible to increase photoelectricconversion efficiency of the photoelectric conversion film. Accordingly,the photoelectric conversion film according to the second embodiment ofthe present disclosure can be appropriately used for the photoelectricconversion film of the solid-state image sensor and it is possible toincrease sensitivity of the solid-state image sensor.

3.2. Configuration of Photoelectric Conversion Element According toSecond Embodiment

Since a configuration of the photoelectric conversion element accordingto the second embodiment of the present disclosure is substantially thesame as the configuration described in the first embodiment of thepresent disclosure, detailed description thereof will be omitted.

That is, the photoelectric conversion element according to the secondembodiment of the present disclosure is different from the firstembodiment in that the photoelectric conversion layer 108 is configuredas the photoelectric conversion film including the transparent compoundrepresented by General formula (3) or (4).

3.3. Example According to Second Embodiment

Hereinafter, the photoelectric conversion film according to the secondembodiment of the present disclosure will be described in detail withreference to examples and comparative examples. However, the followingexamples are only examples and the photoelectric conversion filmaccording to the second embodiment of the present disclosure are notlimited to the following examples.

(Manufacturing of Photoelectric Conversion Element)

In addition, the photoelectric conversion element according to thesecond embodiment of the present disclosure was manufactured by thefollowing manufacturing methods. However, structures and manufacturingmethods of photoelectric conversion elements to be described below areonly examples. The structure and the manufacturing method of thephotoelectric conversion element according to the second embodiment ofthe present disclosure are not limited to the following examples.

Example 8

First, a glass substrate with an ITO electrode was washed by UV/ozonetreatment. In addition, a film thickness of an ITO film corresponding toa lower electrode in the glass substrate was 50 nm. Next, the glasssubstrate was put into an organic deposition apparatus, a pressure wasdecreased to less than or equal to 1×10⁻⁴ Pa, and5,6,11,12,17,18-hexaazatrinaphthylene (HATNA) represented by thefollowing structural formula and quinacridone was deposited by theresistance heating method while rotating a substrate holder. Inaddition, deposition was performed at a deposition rate of 0.1 nm/secsuch that a ratio of HATNA and quinacridone became 1:1, and a film of100 nm in total was formed to form the photoelectric conversion layer.HATNA is a transparent compound that has a structure represented byGeneral formula (3).

Further, a film of AlSiCu was formed above the photoelectric conversionlayer at a film thickness of 100 nm by the deposition method to form anupper electrode. By the above manufacturing method, the photoelectricconversion element including a photoelectric conversion area of 1 mm×1mm was manufactured.

Example 9

A photoelectric conversion element was manufactured by the same methodas in Example 8 except that2,3,8,9,14,15-hexachloro-5,6,11,12,17,18-hexaazatrinaphthylene(C16-HATNA) represented by the following structural formula was usedinstead of HATNA used in Example 8. C16-HATNA is a transparent compoundthat has a structure represented by General formula (3).

Example 10

A photoelectric conversion element was manufactured by the same methodas in Example 8 except that4,4′-bis(4,6-diphenyl-1,3,5-triazin-2-yl)biphenyl (BTB) represented bythe following structural formula was used instead of HATNA used inExample 8. BTB is a transparent compound that has a structurerepresented by General formula (4).

Comparative Example 16

A photoelectric conversion element was manufactured by the same methodas in Example 8 except that a photoelectric conversion layer was formedat a film thickness of 100 nm using only quinacridone instead of usingHATNA and quinacridone used in Example 8.

Comparative Example 17

A photoelectric conversion element was manufactured by the same methodas in Example 8 except that 4,6-bis(3,5-di(pyridin-4-yl)phenyl)-2-methylpyrimidine (B4PyMPM) represented by the following structural formula wasused instead of HATNA used in Example 8. In addition, B4PyMPM is atransparent compound having a value of an LUMO level that is close to anLUMO level of HATNA.

Comparative Example 18

A photoelectric conversion element was manufactured by the same methodas in Example 8 except that a photoelectric conversion layer was formedat a film thickness of 100 nm using only subphthalocyanine chloride(SubPc-Cl) represented by the following structural formula instead ofHATNA and quinacridone used in Example 8. In addition, SubPc-Cl is acompound having a value of an LUMO level that is close to an LUMO levelof HATNA, but absorbs light of a visible light band.

Comparative Example 19

A photoelectric conversion element was manufactured by the same methodas in Example 8 except that SubPc-Cl was used instead of HATNA used inExample 8.

In addition, in the above example, as quinacridone and SubPc-Cl,sublimated and purified products purchased from Tokyo Chemical IndustryCo., Ltd. were used. In addition, as HATNA, C16-HATNA and BTB,sublimated and purified products purchased from Lumtec Corp. (Taiwan)were used.

(Evaluation of optical conversion characteristics) First, photoelectricconversion efficiency and spectral characteristics were evaluated forthe above manufactured photoelectric conversion elements according toExamples 8 to 10 and Comparative examples 16 to 19.

Here, photoelectric conversion efficiency was evaluated by measuringexternal quantum efficiency using the semiconductor parameter analyzer.Specifically, light having a wavelength of 565 nm was radiated to thephotoelectric conversion element at an intensity of 1.62 microwatts persquare centimeter from a light source through a filter, and externalquantum efficiency was computed from a light current value and a darkcurrent value when the bias voltage applied between electrodes was setto −1 V.

In addition, spectral characteristics were evaluated using an incidentphoton to current conversion efficiency (IPCE) measuring device suchthat a change rate of external quantum efficiency with respect to awavelength was measured and a full width at half maximum of a peak wascomputed. Specifically, light of 1.62 microwatts per square centimeterwas radiated to the photoelectric conversion element from a light sourcethrough a filter, and external quantum efficiency was computed from alight current value and a dark current value when the bias voltageapplied between electrodes was set to −1 V. In addition, the aboveexternal quantum efficiency was computed for each wavelength and a fullwidth at half maximum of a peak was calculated.

The above evaluation results are shown in the following Table 4. Inaddition, IPCE measurement results of Example 8 and Comparative example19 are shown in FIG. 4 . In Table 4, “QD” represents quinacridone, and“-” represents that no corresponding material was added. FIG. 4 showsthe graph of IPCE measurement results of Example 8 and Comparativeexample 19, a solid line represents Example 8 and a dashed linerepresents Comparative example 19.

TABLE 4 P type N type External Full width at photoelectric photoelectricquantum half conversion conversion efficiency maximum of materialmaterial (%) peak (nm) Example 8 QD HATNA 43 130 Example 9 QD Cl6-HATNA28 130 Example 10 QD BTR 37 130 Comparative QD — 9 135 example 16Comparative QD B4PyMPM 2.3 140 example 17 Comparative SubPc—Cl — 3 165example 18 Comparative QD SubPc—Cl 39 180 example 19

As shown in the results in Table 4, it can be understood that Examples 8to 10 serving as the photoelectric conversion element according to thesecond embodiment of the present disclosure have significantly higherexternal quantum efficiency than Comparative examples 16 to 18.

Here, Comparative example 19 has high external quantum efficiencysimilar to Examples 8 to 10, but SubPc-Cl absorbing visible light wasused as the n type photoelectric conversion material. For this reason,since a full width at half maximum of a peak according to IPCEmeasurement in Comparative example 19 is wider than those of Examples 8to 10, it is not preferable. Specifically, as shown in FIG. 4 , since apeak of a profile of external quantum efficiency with respect to awavelength in Comparative example 19 is wider than a peak of Example 8,red light having a wavelength of greater than or equal to 600 nm or bluelight having a wavelength of less than 450 nm can also be absorbed, itis not preferable.

On the other hand, as shown in FIG. 4 , it can be understood thatExample 8 has a sharper peak of a profile of external quantum efficiencywith respect to a wavelength than Comparative example 19, and can absorbgreen light having a wavelength of greater than or equal to 450 nm andless than 600 nm more selectively, and perform photoelectric conversion.Accordingly, it can be understood that, since Example 8 has higherselectivity of a wavelength of light to be absorbed than Comparativeexample 19, it is appropriate for the photoelectric conversion elementof the solid-state image sensor.

Subsequently, in Examples 8 to 10 and Comparative examples 16 to 19,HOMO levels and LUMO levels of the p type photoelectric conversionmaterial and the n type photoelectric conversion material used in thephotoelectric conversion layer were measured.

In addition, in order to measure the HOMO level, a sample in which eachorganic material was formed into a 20 nm film by the deposition methodon a silicon substrate that had been treated with UV/ozone was used. TheHOMO level was computed for the sample in which each organic materialwas formed into a film using the UPS method.

In addition, in order to measure the LUMO level, a sample in which eachorganic material was formed into a 50 nm film by the deposition methodon a quartz substrate that had been treated with UV/ozone was used.First, a transmittance and a reflectance of the sample were measured andan absorption coefficient alpha with respect to a wavelength wascomputed. Next, an absorption end of a visible light area of thecomputed absorption coefficient alpha was computed as an HOMO-LUMO gap,and the HOMO-LUMO gap was subtracted from the HOMO level to compute theLUMO level.

The measured HOMO level and LUMO level of the p type photoelectricconversion material and the n type photoelectric conversion material areshown in the following Table 5. In Table 5, “QD” representsquinacridone.

TABLE 5 HOMO LUMO (eV) (eV) HATNA −6.9 −3.8 Cl6-HATNA −7.8 −5.1 BTB −6.9−3.6 B4PyMPM −7.6 −4.05 SubPc—Cl −5.7 −3.7 QD −5.55 −3.55

As shown in the results in Table 5, an LUMO level difference between“HATNA” and “QD” used in Example 8 is 0.25 eV. An LUMO level differencebetween “C16-HATNA” and “QD” used in Example 9 is 1.55 eV. An LUMO leveldifference between “BTB” and “QD” used in Example 10 is 0.05 eV. Asshown in the results in Table 4, it can be understood that Example 8 hasan LUMO level difference that is included in a preferable range (greaterthan or equal to 0.1 eV and less than or equal to 1.0 eV) in the secondembodiment of the present disclosure and has higher external quantumefficiency than Examples 9 and 10 having LUMO level differences outsideof the preferable range.

In addition, “B4PyMPM” used in Comparative example 17 is a transparentcompound that has an LUMO level close to that of “HATNA” serving as thetransparent material according to the second embodiment of the presentdisclosure. However, Comparative example 17 has significantly lowerexternal quantum efficiency than Examples 8 to 10. Accordingly, it canbe understood that, in the photoelectric conversion film according tothe second embodiment of the present disclosure, it is important thatthe transparent compound have a structure represented by General formula(3) or (4) in order to increase external quantum efficiency.

Specifically, when the transparent compound represented by Generalformula (3) or (4) forms the bulk hetero mixed film with the organic dyecompound, crystal fine particles of sizes that are appropriate forcharge separation can be formed. Accordingly, external quantumefficiency is considered to increase in the photoelectric conversionfilm using the transparent compound represented by General formula (3)or (4). On the other hand, since “B4PyMPM” having no structurerepresented by General formula (3) or (4) is unable to form crystal fineparticles of sizes that are appropriate for charge separation, it isconsidered difficult to increase external quantum efficiency.

(Detailed examination of transparent compound represented by Generalformula (4)) Hereinafter, a more preferable structure of the transparentcompound represented by General formula (4) was examined.

(Synthesis of transparent compound represented by General formula (4))First, a synthesizing method of BTB-1 to BTB-6 that are the transparentcompound represented by General formula (4) and represented by thefollowing structure will be described. Purity of the synthesized BTB-1to BTB-6 was examined using high performance liquid chromatography(HPLC), and ¹HNMR and matrix assisted laser desorption/ionization-timeof flight massspectrometry (MALDI-TOFMS) were used for identification.However, the following synthesizing method to be described is only anexample, and the synthesizing method of the transparent compoundrepresented by General formula (4) is not limited to the followingexample.

Synthesis of BTB-1

BTB-1 was synthesized through the following Reaction formula 5.

Biphenyl dicarbonyl dichloride (28.8 g, 103 mmol), thionyl chloride(SOCl₂) (8.43 g, 70.9 mmol), orthodichlorobenzene (405 mL), aluminumchloride (30.6 g, 230 mmol), and benzonitrile (61.1 g, 444 mmol) wereadded to a four-neck flask under an argon (Ar) atmosphere. The mixturewas sufficiently stirred and then was heated and stirred for 30 minutesat 150 degrees Celsius. Subsequently, a temperature was decreased to 120degrees Celsius, ammonium chloride (23.1 g, 432 mmol) was added, and themixture was heated and stirred again for 4 hours at 170 degrees Celsius.

After a temperature was cooled to room temperature, a reaction solutionwas mixed with a solution in which 28% ammonia water (400 mL) andmethanol (3 L) were mixed, and a precipitated solid was extracted byfiltration. The precipitated solid was suspended and washed with purewater (1 L), and suspended and washed again with methanol (1 L) toobtain a gray solid. Additionally, the obtained gray solid wassublimated and purified twice to obtain BTB-1 (11.4 g, yield 18%) thatis a target compound.

Synthesis of BTB-2

BTB-2 was synthesized by the same method as in the above Reactionformula 5 except that 4-fluoro-benzonitrile was used instead ofbenzonitrile.

Synthesis of BTB-3

BTB-3 was synthesized by the same method as in the above Reactionformula 5 except that 4-trifluoromethyl benzonitrile was used instead ofbenzonitrile.

Synthesis of BTB-4

BTB-4 was synthesized by the same method as in the above Reactionformula 5 except that 4-chloro-benzonitrile was used instead ofbenzonitrile.

Synthesis of BTB-5

BTB-5 was synthesized by the same method as in the above Reactionformula 5 except that tetra fluoro diphenyl carbonyl chloride was usedinstead of diphenyl carbonyl chloride.

Synthesis of BTB-6

BTB-6 was synthesized by the same method as in the above Reactionformula 5 except that tetra fluoro diphenyl carbonyl chloride was usedinstead of diphenyl carbonyl chloride and 4-chloro-benzonitrile was usedinstead of benzonitrile.

(Evaluation of Spectral Characteristics of Transparent CompoundRepresented by General Formula (4))

Next, a monolayer film sample of the transparent compound represented byGeneral formula (4) was manufactured and spectral characteristics of thetransparent compound represented by General formula (4) were identified.

Specifically, a sample in which each organic material (BTB-1 to BTB-6)was formed into a 50 nm film by the deposition method on a quartzsubstrate that had been treated with UV/ozone at a deposition rate of0.05 nm/sec was manufactured. Next, a transmittance and a reflectance ofthe manufactured sample were measured by the spectrophotometer (JASCOV-570), and an absorption coefficient alpha with respect to a wavelengthwas computed. Measurement results of the absorption coefficient alphaare shown in FIG. 5 . FIG. 5 shows the graph of the absorptioncoefficient alpha in a band of 300 nm to 800 nm of BTB-1 to BTB-6.

As shown in FIG. 5 , it can be understood that all of BTB-1 to BTB-6 ofthe transparent compound represented by General formula (4) have a lowabsorption coefficient in a wavelength band of 400 nm to 800 nm. Inother words, it can be understood that BTB-1 to BTB-6 of the transparentcompound represented by General formula (4) are transparent compoundsthat do not absorb light of a visible light band.

(Evaluation of Electrical Characteristics of Transparent CompoundRepresented by General Formula (4))

Subsequently, a photoelectric conversion element was manufactured usingthe transparent compound represented by General formula (4) andelectrical characteristics of the photoelectric conversion element wereevaluated.

Example 11

First, a glass substrate with an ITO electrode was washed by UV/ozonetreatment. In addition, a film thickness of an ITO film corresponding toa lower electrode in the glass substrate was 50 nm. Next, the glasssubstrate was put into an organic deposition apparatus, a pressure wasdecreased to less than or equal to 1×10⁻⁵ Pa, and the above synthesizedBTB-1 and quinacridone (a sublimated and purified product manufacturedby Tokyo Chemical Industry Co., Ltd.) were deposited by the resistanceheating method while rotating a substrate holder. In addition,deposition was performed at a deposition rate of 0.03 nm/sec and 0.07nm/sec such that a ratio of BTB-1 and quinacridone became 3:7, and afilm of 120 nm in total was formed to form the photoelectric conversionlayer.

Subsequently, a film of LiF of 0.5 nm was deposited and formed above thephotoelectric conversion layer at 0.002 nm/sec, and further a film ofAlSiCu was formed at a film thickness of 100 nm by the deposition methodto form an upper electrode. By the above method, the photoelectricconversion element including a photoelectric conversion area of 1 mm×1mm was manufactured.

Examples 12 to 16

A photoelectric conversion element was manufactured by the same methodas in Example 11 except that BTB-2 to BTB-6 were used instead of BTB-1used in Example 11.

Comparative Example 20

A photoelectric conversion element was manufactured by the same methodas in Example 11 except that quinacridone was used instead of BTB-1 usedin Example 11 and only quinacridone was used to form the photoelectricconversion layer.

Photoelectric conversion efficiency was evaluated for the abovemanufactured photoelectric conversion elements according to Examples 11to 16 and Comparative example 20. Here, photoelectric conversionefficiency was evaluated by measuring external quantum efficiency usingthe semiconductor parameter analyzer. Specifically, light was radiatedto the photoelectric conversion element at an intensity of 1.62microwatts per square centimeter from a light source through a filter,and external quantum efficiency was computed from a light current valueand a dark current value when the bias voltage applied betweenelectrodes was set to −1 V.

Evaluation results are shown in the following Table 6. In Table 6, “QD”represents quinacridone and “-” represents that no correspondingmaterial was added.

In addition, external quantum efficiency was evaluated before and afterannealing treatment. The annealing treatment was performed by heatingthe photoelectric conversion element using a hot plate in a glove box.Here, a heating temperature was 160 degrees Celsius and a heating timewas 210 minutes.

TABLE 6 Before annealing After annealing P type N type External Externalphotoelectric photoelectric quantum quantum conversion conversionefficiency Dark current efficiency Dark current material Material (%)(A/cm²) (%) (A/cm²) Example 11 QD BTB-1 21 1.40 × 10⁻⁹  20 9.40 × 10⁻¹⁰Example 12 QD BTB-2 34 8.85 × 10⁻¹⁰ 31 4.20 × 10⁻¹⁰ Example 13 QD BTB-337 8.40 × 10⁻¹⁰ 52 3.00 × 10⁻¹⁰ Example 14 QD BTB-4 33 1.20 × 10⁻⁹  334.60 × 10⁻¹⁰ Example 15 QD BTB-5 34 9.60 × 10⁻¹⁰ 31 4.90 × 10⁻¹⁰ Example16 QD BTB-6 41 7.50 × 10⁻¹⁰ 45 4.20 × 10⁻¹⁰ Comparative QD — 8 1.40 ×10⁻⁹  6 9.90 × 10⁻¹⁰ example 20

As shown in the results in Table 6, it can be understood that Examples11 to 16 have higher external quantum efficiency than Comparativeexample 20. In addition, it can be understood that, since Examples 11 to16 have external quantum efficiency that is not significantly decreasedbefore and after annealing, BTB-1 to BTB-6 of the transparent compoundrepresented by General formula (4) have a high heat resistance.

Further, comparing Example 11 and Examples 12 to 16, it can beunderstood that Examples 12 to 16 using BTB-2 to BTB-6 including anelectron attracting group as a substituent have higher external quantumefficiency than Example 11 using BTB-1 including no electron attractinggroup as a substituent. Accordingly, it is understood that thetransparent compound represented by General formula (4) preferablyincludes an electron attracting group as a substituent. Specifically, itcan be understood in General formula (4) that at least one ofsubstituents of Ar₁ to Ar₄ and R₄₁ to R₄₈ is preferably the electronattracting group.

As can be understood from the above results, when the photoelectricconversion element according to the second embodiment of the presentdisclosure includes the transparent compound represented by Generalformula (3) or (4), it is possible to increase photoelectric conversionefficiency while selectively absorbing light of a specific wavelength.Accordingly, since the photoelectric conversion element according to thesecond embodiment of the present disclosure can be appropriately used asthe photoelectric conversion element in the solid-state image sensor, itis possible to increase sensitivity of the solid-state image sensor.

4. THIRD EMBODIMENT 4.1. Configuration of Photoelectric ConversionElement According to Third Embodiment

Next, the photoelectric conversion element according to the thirdembodiment of the present disclosure will be described. Thephotoelectric conversion element according to the third embodiment ofthe present disclosure is a photoelectric conversion element thatincludes a hole blocking layer and a difference between an ionizationpotential of the hole blocking layer and a work function of an electrodethat is adjacent to the hole blocking layer is greater than or equal to2.3 eV.

Specifically, same as the first embodiment of the present disclosure, aphotoelectric conversion element according to the third embodiment ofthe present disclosure includes a substrate 102, a lower electrode 104disposed above the substrate 102, an electron blocking layer 106disposed above the lower electrode 104, a photoelectric conversion layer108 disposed above the electron blocking layer 106, a hole blockinglayer 110 disposed above the photoelectric conversion layer 108, and anupper electrode 112 disposed above the hole blocking layer 110. Inaddition, in the photoelectric conversion element according to the thirdembodiment of the present disclosure, the difference between theionization potential of the hole blocking layer 110 and the workfunction of the upper electrode 112 is greater than or equal to 2.3 eV.In addition, the ionization potential of the hole blocking layer 110corresponds to an absolute value of energy of the HOMO level of thecompound forming the hole blocking layer 110.

In general, in the photoelectric conversion element used in thesolid-state image sensor, in many cases, in order to increasesensitivity, a voltage is applied from the outside to increasephotoelectric conversion efficiency and a response speed. However, whenthe voltage is applied to the photoelectric conversion element from theoutside, since the number of holes and electrons introduced from theelectrode due to an external electric field increases, regardless ofincidence of light, a flowing dark current increases. In thephotoelectric conversion element used in the solid-state image sensor,in order to extract a difference between a dark current when no light isincident and a light current when light is incident as a signal, whenthe dark current is increased, an S/N ratio may decrease.

In particular, when a temperature of a usage environment is high (forexample, greater than or equal to 50 degrees Celsius), since the darkcurrent flowing in the photoelectric conversion element increasesaccording to an increase in the temperature, it is necessary to suppressthe dark current.

In the photoelectric conversion element according to the thirdembodiment of the present disclosure, by use of the hole blocking layerin which the difference between the ionization potential of the holeblocking layer and the work function the adjacent electrode is greaterthan or equal to 2.3 eV, it is possible to suppress the dark current. Inparticular, in the photoelectric conversion element according to thethird embodiment of the present disclosure, even in a high temperatureenvironment (for example, greater than or equal to 50 degrees Celsius),it is possible to suppress the dark current from increasing.

In addition, it is preferable that an energy difference between theionization potential (that is, an absolute value of the HOMO level ofthe compound forming the hole blocking layer 110) of the hole blockinglayer 110 and the work function of the adjacent electrode be higher.Accordingly, an upper limit of the energy difference between theionization potential of the hole blocking layer 110 and the workfunction of the adjacent electrode is not particularly limited, but maybe, for example, less than or equal to 3.0 eV.

For example, when the upper electrode 112 adjacent to the hole blockinglayer 110 is formed of indium tin oxide (ITO) that is a transparentconductive material, since a work function of the indium tin oxide is4.8 eV, the HOMO level of the compound forming the hole blocking layer110 is preferably less than or equal to −6.8 eV, and more preferably,less than or equal to −7.1 eV.

In addition, the upper electrode 112 adjacent to the hole blocking layer110 may be formed of a conductive material, but the material forming theupper electrode 112 is not limited to the above indium tin oxide. Forexample, the upper electrode 112 may be formed of a transparentconductive material, and may be formed of indium zinc oxide (IZO), agraphene transparent electrode or the like.

In addition, the LUMO level of the compound forming the hole blockinglayer 110 is preferably the same as or shallower (an absolute value issmaller) than that of the n type photoelectric conversion material ofthe adjacent photoelectric conversion layer 108. In this case, the holeblocking layer 110 can efficiently move electrons generated in thephotoelectric conversion layer 108 due to photoelectric conversion tothe upper electrode 112. In addition, in order to more efficiently moveelectrons generated in the photoelectric conversion layer 108 to theupper electrode 112, it is preferable that a difference between the LUMOlevel of the compound forming the hole blocking layer 110 and the LUMOlevel of the n type photoelectric conversion material of the adjacentphotoelectric conversion layer 108 be smaller.

For example, when the n type photoelectric conversion material includedin the photoelectric conversion layer 108 is the subphthalocyaninederivative, the LUMO level of the compound forming the hole blockinglayer 110 is preferably greater than or equal to −5.5 eV and less thanor equal to −3.3 eV, and more preferably, greater than or equal to −5.0eV and less than or equal to −3.5 eV.

Further, a film thickness of the hole blocking layer 110 is preferablygreater than or equal to 1 nm and less than or equal to 50 nm, morepreferably greater than or equal to 2 nm and less than or equal to 30nm, and most preferably greater than or equal to 5 nm and less than orequal to 10 nm. When a film thickness of the hole blocking layer 110 iswithin the above range, the hole blocking layer 110 can efficiently moveelectrons from the photoelectric conversion layer 108 to the upperelectrode 112 while suppressing holes from being introduced from theupper electrode 112.

Here, it is preferable that the hole blocking layer 110 include thecompound represented by the following General formula (5).

In General Formula (5) above, R₅₀ represents any substituent selectedfrom the group consisting of hydrogen, a halogen, a hydroxy group, analkoxy group, a cyano group, a nitro group, a silylalkyl group, asilylalkoxy group, an arylsilyl group, a thioalkyl group, a thioarylgroup, a sulfonyl group, an arylsulfonyl group, an alkylsulfonyl group,an amino group, an alkylamino group, an arylamino group, an acyl group,an acylamino group, an acyloxy group, a carboxy group, a carboxamidogroup, a carboalkoxy group, a substituted or unsubstituted alkyl group,a substituted or unsubstituted cycloalkyl group, a substituted orunsubstituted aryl group, and a substituted or unsubstituted heteroarylgroup, and Ar₅ to Ar₈ represent a substituted or unsubstitutedheteroaryl group.

The compound represented by the above General formula (5) has a deepHOMO level (an absolute value of energy of the HOMO level is high) and ahigh ionization potential. Accordingly, in the compound represented byGeneral formula (5), it is possible to set a difference between theionization potential of the hole blocking layer 110 and a work functionof the adjacent upper electrode 112 to greater than or equal to 2.3 eV.Therefore, the hole blocking layer 110 can suppress holes from beingintroduced from the upper electrode 112 due to an external electricfield and it is possible to suppress the dark current even in a hightemperature environment.

In addition, in General formula (5), it is preferable that at least oneof substituents of Ar₅ to Ar₈ and R₅₀ be an electron attracting group.In other words, the compound represented by General formula (5)preferably has at least one electron attracting group as thesubstituent. In this case, in the compound represented by Generalformula (5), since the HOMO level becomes deeper (an absolute valueincreases) and the ionization potential increases, a difference from awork function of the adjacent upper electrode 112 can become greater.Since the hole blocking layer 110 including the compound represented byGeneral formula (5) can further suppress holes from being introducedfrom the upper electrode 112, it is possible to further suppress thedark current.

In addition, in order to set the HOMO level of the compound representedby General formula (5) to a deeper value, it is preferable that thecompound represented by General formula (5) include more electronattracting groups and it is preferable that an electron withdrawingability of the substituent to be included be set to be higher. In thiscase, since the compound represented by General formula (5) can furthersuppress holes from being introduced from the upper electrode 112, it ispossible to further suppress the dark current.

In the above description, the electron attracting groups may be, forexample, a halogen, a cyano group, a nitro group, a sulfonyl group, anarylsulfonyl group, an alkylsulfonyl group, an acyl group, an acylaminogroup, an acyloxy group, an imide group, a carboxy group, a carboxamidogroup, a carboalkoxy group, a halogenated alkyl group, and a halogenatedaryl group.

As a preferable specific example of the compound represented by Generalformula (5) above, a compound represented by the following structuralformula can be exemplified. However, the compound represented by Generalformula (5) according to the third embodiment of the present disclosureis not limited to the following exemplary compounds.

In addition, in the photoelectric conversion element according to thethird embodiment of the present disclosure, since a configuration of thesubstrate 102, the lower electrode 104, the electron blocking layer 106,the photoelectric conversion layer 108 and the upper electrode 112 issubstantially the same as that of the first embodiment, detaileddescription thereof will be omitted. However, the photoelectricconversion layer 108 is preferably formed in the above-describedphotoelectric conversion film according to the first and secondembodiments.

As described above, the photoelectric conversion element according tothe third embodiment of the present disclosure is possible to suppressthe dark current when a hole blocking layer having an ionizationpotential that has a difference of greater than or equal to 2.3 eV fromthe work function of the adjacent electrode is used, In particular, inthe photoelectric conversion element according to the third embodimentof the present disclosure, even in a high temperature environment (forexample, greater than or equal to 50 degrees Celsius), it is possible tosuppress the dark current from increasing.

In addition, in the photoelectric conversion element according to thethird embodiment of the present disclosure, when the compoundrepresented by General formula (5) is used in the hole blocking layer,it is possible to set an energy difference between the ionizationpotential of the hole blocking layer and the work function of theadjacent electrode to greater than or equal to 2.3 eV. Accordingly, inthe photoelectric conversion element according to the third embodimentof the present disclosure, it is possible to suppress the dark currentwhile maintaining high photoelectric conversion efficiency.

4.2. Example According to Third Embodiment

Hereinafter, the photoelectric conversion film according to the thirdembodiment of the present disclosure will be described in detail withreference to examples and comparative examples. However, the followingexamples are only examples and the photoelectric conversion filmaccording to the third embodiment of the present disclosure are notlimited to the following examples.

(Synthesis of Compound Represented by General Formula (5))

First, a synthesizing method of the compound represented by Generalformula (5) will be described. Specifically, B4PyMPM and B3PyMPMrepresented by the following structural formulae were synthesized. Thesynthesized B4PyMPM and B3PyMPM were identified using ¹HNMR and FD-MS.However, the synthesizing method to be described below is only anexample, and the synthesizing method of the compound represented byGeneral formula (5) is not limited to the following example.

Synthesis of B4PyMPM

B4PyMPM was synthesized through the following reaction formulae 6 and 7.

First, 4,6-dichloro-2-methyl-pyrimidine (5.0 g, 30.7 mmol),3,5-dichlorophenyl boronic acid (12.9 g, 67.7 mmol),dichlorobis(triphenylphosphine)palladium(II) (PdCl₂(PPh₃)₂) (1.07 g,0.96 mmol), and a sodium carbonate aqueous solution (1.0 mol/L, 150 ml)were added to a three-neck flask under a nitrogen atmosphere, and themixture was stirred for 10 minutes in an acetonitrile (500 ml) solvent.A reaction solution was mixed with water, and a precipitated solid wasextracted by filtration. The precipitated solid was suspended and washedwith pure water to obtain a white solid. Additionally, the obtainedwhite solid was recrystallized to obtain an intermediate compound A(11.8 g, yield 72%).

Next, the intermediate compound A (4.6 g, 11.9 mmol), 4-pyridineboronicacid pinacol ester (10.8 g, 52.6 mmol),tris(dibenzylideneacetone)dipalladium(0) (Pd₂(dba)₃) (0.43 g, 0.48mmol), tricyclohexylphosphine (PCy₃) (0.322 g, 1.15 mmol), and apotassium phosphate aqueous solution (1.35 mol/L, 138 ml) were added toa three-neck flask under a nitrogen atmosphere, and the mixture wasstirred for 24 hours in a dioxane (440 ml) solvent. A reaction solutionwas mixed with water, and a precipitated solid was extracted byfiltration. The precipitated solid was suspended and washed with purewater to obtain a white solid. Additionally, the obtained white solidwas sublimated and purified to obtain B4PyMPM (6.67 g, yield 77%) thatis a target compound.

Synthesis of B3PyMPM

In Reaction formula 7, B3PyMPM was synthesized by the same method as inReaction formula 6 or 7 except that 3-pyridylboronic acid pinacol esterwas used instead of 4-Pyridineboronic acid pinacol ester.

(Evaluation of Photoelectric Conversion Element)

In addition, the photoelectric conversion element according to the thirdembodiment of the present disclosure was manufactured by the followingmanufacturing methods. However, structures and manufacturing methods ofphotoelectric conversion elements to be described below are onlyexamples. The structure and the manufacturing method of thephotoelectric conversion element according to the third embodiment ofthe present disclosure are not limited to the following examples.

Example 17

First, a Si substrate with an ITO electrode was washed by UV/ozonetreatment. In addition, a film thickness of an ITO film corresponding toa lower electrode in the Si substrate was 100 nm. Next, the Si substratewas put into an organic deposition apparatus, a pressure was decreasedto less than or equal to 1×10⁻⁵ Pa, and F6-SubPc-Cl (a sublimated andpurified product manufactured) and t-butyl quinacridone (a sublimatedand purified product manufactured by Tokyo Chemical Industry Co., Ltd.)were deposited by a resistance heating method while rotating a substrateholder. In addition, deposition was performed at a deposition rate of0.05 nm/see such that a ratio of F6-SubPc-Cl and t-butyl quinacridone(BQD) became 1:1, and a film of 120 nm in total was formed to form thephotoelectric conversion layer.

Next, the above synthesized B4PyMPM was deposited above thephotoelectric conversion layer by the resistance heating method. Adeposition rate was 0.05 nm/sec, and a 5 nm film was formed to form thehole blocking layer. Subsequently, an ITO film was formed above the holeblocking layer by the sputtering method at a film thickness of 50 nm,thereby forming the upper electrode. In addition, the lower electrodeand the upper electrode were formed to have a photoelectric conversionarea of 0.5 mm×0.5 mm. Further, heat treatment of an element forming theupper electrode was performed for 3.5 hours at 160 degrees Celsius on ahot plate in a glove box replaced with nitrogen to manufacture thephotoelectric conversion element. Hereinafter, structural formulae ofF6-SubPc-Cl and t-butyl quinacridone (BQD) used in the photoelectricconversion layer will be illustrated.

Example 18

A photoelectric conversion element was manufactured by the same methodas in Example 17 except that the hole blocking layer was formed into a10 nm film.

Example 19

A photoelectric conversion element was manufactured by the same methodas in Example 17 except that the hole blocking layer was formed into a20 nm film.

Example 20

A photoelectric conversion element was manufactured by the same methodas in Example 17 except that the hole blocking layer was formed usingB3PyMPM instead of B4PyMPM.

Example 21

A photoelectric conversion element was manufactured by the same methodas in Example 17 except that the hole blocking layer was formed usingHATNA represented by the following structural formula instead ofB4PyMPM.

Example 22

A photoelectric conversion element was manufactured by the same methodas in Example 17 except that the hole blocking layer was formed usingMe6-HATNA represented by the following structural formula instead ofB4PyMPM.

Comparative Example 23

A photoelectric conversion element was manufactured by the same methodas in Example 17 except that no hole blocking layer was formed.

(Evaluation Result)

First, HOMO levels and LUMO levels of the compounds (B4PyMPM, B3PyMPM,HATNA, Me6-HATNA, F6-SubPc-Cl and BQD) used in each layer of thephotoelectric conversion element according to Examples 17 to 20 andComparative examples 21 to 23 were measured.

In addition, in order to measure the HOMO level, a sample in which eachcompound was formed into a 20 nm film by the deposition method on asilicon substrate that had been treated with UV/ozone was used. The HOMOlevel was computed for the sample in which each compound was formed intoa film using the UPS method.

In addition, in order to measure the LUMO level, a sample in which eachorganic material was formed into a 50 nm film by the deposition methodon a quartz substrate that had been treated with UV/ozone was used.First, a transmittance and a reflectance of the sample were measured andan absorption coefficient alpha with respect to a wavelength wascomputed. Next, an absorption end of a visible light area of thecomputed absorption coefficient alpha was computed as an HOMO-LUMO gap,and the HOMO-LUMO gap was subtracted from the HOMO level to compute theLUMO level.

The measured HOMO level and LUMO level of each compound are shown in thefollowing Table 7. In addition, a work function of ITO used in the upperelectrode was 4.8 eV.

TABLE 7 HOMO LUMO (eV) (eV) B4PyMPM −7.6 −4.05 B3PyMPM −7.2 −3.65 HATNA−6.9 −3.8 Me6-HATNA −6.3 −3.5 F6-SubPc—Cl −6.3 −4.2 BQD −5.65 −3.55

As shown in the results in Table 7, it can be understood that adifference between an ionization potential (an absolute value of theHOMO level) of B4PyMPM used in the hole blocking layer of Examples 17 to19 and a work function of the upper electrode (ITO) is 2.8 eV and isincluded in a preferable range in the third embodiment of the presentdisclosure. In addition, it can be understood that a difference betweenan ionization potential of B3PyMPM used in the hole blocking layer ofExample 20 and a work function of the upper electrode is 2.4 eV and isincluded in a preferable range in the third embodiment of the presentdisclosure.

On the other hand, it can be understood that a difference between anionization potential of HATNA used in the hole blocking layer ofComparative example 21 and a work function of the upper electrode is 2.1eV and is outside of a preferable range in the third embodiment of thepresent disclosure. In addition, it can be understood that a differencebetween an ionization potential of Me6-HATNA used in the hole blockinglayer of Comparative example 22 and a work function of the upperelectrode is 1.5 eV and is outside of a preferable range in the thirdembodiment of the present disclosure.

In addition, photoelectric conversion efficiency was evaluated for theabove manufactured photoelectric conversion elements according toExamples 17 to 20 and Comparative examples 21 to 23. In addition, allevaluations of the photoelectric conversion elements according toExamples 17 to 20 and Comparative examples 21 to 23 were performed undera high temperature environment at 60 degrees Celsius.

Photoelectric conversion efficiency was evaluated by measuring externalquantum efficiency using a semiconductor parameter analyzer.Specifically, light having a wavelength of 565 nm was radiated to thephotoelectric conversion element from a light source at an intensity of1.62 microwatts per square centimeter through a filter, and externalquantum efficiency was computed from a light current value and a darkcurrent value when the bias voltage applied between electrodes was setto −1 V or −5 V. Here, the condition in which the bias voltage appliedbetween electrodes is set to −5 V may increase external quantumefficiency, but also increase the dark current.

The above evaluation results are shown in the following Table 8. InTable 8, “-” represents that no corresponding layer was formed. Inaddition, “energy difference” represents an energy difference betweenthe ionization potential of the hole blocking layer and a work functionof the upper electrode and was computed by obtaining a differencebetween an absolute value of the HOMO level of each compound forming thehole blocking layer and a work function (4.8 eV) of the upper electrode(ITO) formed by ITO.

TABLE 8 Bias voltage-1 V Bias voltage-5 V Hole blocking layer ExternalExternal Energy Film quantum Dark quantum Dark difference thicknessefficiency current efficiency current Compound (eV) (nm) (%) (A/cm²) (%)(A/cm²) Example 17 B4PyMPM 2.8 5 48 5.0 × 10⁻¹¹ 65 2.0 × 10⁻¹⁰ Example18 B4PyMPM 2.8 10 47 4.0 × 10⁻¹¹ 64 1.2 × 10⁻¹⁰ Example 19 B4PyMPM 2.820 45 3.0 × 10⁻¹¹ 60 9.0 × 10⁻¹¹ Example 20 B3PyMPM 2.4 5 46 5.0 × 10⁻¹¹62 3.0 × 10⁻¹⁰ Comparative HATNA 2.1 5 47 9.0 × 10⁻¹¹ 64 4.7 × 10⁻⁹ example 21 Comparative Me6-HATNA 1.5 5 45 4.0 × 10⁻¹⁰ 60 6.1 × 10⁻⁹ example 22 Comparative — — — 45 1.8 × 10⁻¹⁰ 58 5.8 × 10⁻⁹  example 23

As shown in the results in Tables 7 and 8, it can be understood that, inExamples 17 to 20 according to the third embodiment of the presentdisclosure, the dark current can be decreased at both of the biasvoltages −1 V and −5 V, compared to Comparative example 23 in which nohole blocking layer was provided. In addition, it can be understood thatExamples 17 to 20 can increase external quantum efficiency at both ofthe bias voltages −1 V and −5 V to the same or a greater extent thanComparative example 23. However, Example 19 in which the hole blockinglayer was formed into a 20 nm film can decrease the dark current morethan Examples 17 and 18, but has the same external quantum efficiency asComparative example 23 in which no hole blocking layer was provided.Accordingly, it can be understood that a preferable film thickness ofthe hole blocking layer that can decrease the dark current and increaseexternal quantum efficiency is less than or equal to 20 nm.

In addition, it can be understood that, in Comparative examples 21 and22, since an energy difference between the ionization potential of thehole blocking layer and the work function of the upper electrode isoutside of a preferable range in the third embodiment of the presentdisclosure, the dark current at the bias voltage −5 V increases comparedto Examples 17 to 20, and it is not preferable.

Further, comparing Example 17 and Example 20, it can be understood thatExample 17 can increase external quantum efficiency. The LUMO level ofB4PyMPM used in the hole blocking layer of Example 17 is considered tobe more preferable than the LUMO level of B3PyMPM used in the holeblocking layer of Example 20. Specifically, since the LUMO level (−4.05eV) of B4PyMPM is closer to the LUMO level (−4.2 eV) of F6-SubPc-Cl usedas the n type photoelectric conversion material of the photoelectricconversion layer than the LUMO level (−3.65 eV) of B3PyMPM, electronsgenerated by photoelectric conversion are considered to be moreefficiently moved to the electrode. Accordingly, it is understood thatthe LUMO level of the compound used in the hole blocking layer isshallower (an absolute value is small) than the LUMO level of the n typephotoelectric conversion material of the photoelectric conversion layer,and a difference with the LUMO level of the n type photoelectricconversion material is preferably small.

As can be understood from the above results, in the photoelectricconversion element according to the third embodiment of the presentdisclosure, when there is provided a hole blocking layer in which thedifference between an ionization potential of the hole blocking layerand the work function of the adjacent electrode is greater than or equalto 2.3 eV, it is possible to suppress the dark current. In particular,the photoelectric conversion element according to the third embodimentof the present disclosure can suppress the dark current from increasingunder a high temperature (for example, greater than or equal to 50degrees Celsius) condition and under a high bias voltage condition.

5. APPLICATION EXAMPLE OF PHOTOELECTRIC CONVERSION ELEMENT ACCORDING TOAN EMBODIMENT OF THE PRESENT DISCLOSURE

Hereinafter, an application example of the photoelectric conversionelement including the photoelectric conversion film according to anembodiment of the present disclosure will be described with reference toFIGS. 6 to 8 .

5.1. Configuration of Solid-State Image Sensor

First, a configuration of the solid-state image sensor to which thephotoelectric conversion element according to an embodiment of thepresent disclosure is applied will be described with reference to FIGS.6 and 7 . FIG. 6 is a schematic diagram illustrating a structure of asolid-state image sensor to which the photoelectric conversion elementaccording to an embodiment of the present disclosure is applied.

Here, in FIG. 6 , pixel areas 201, 211 and 231 are areas in which thephotoelectric conversion element including the photoelectric conversionfilm according to an embodiment of the present disclosure are disposed.In addition, control circuits 202, 212 and 242 are arithmetic processingcircuits configured to control each component of the solid-state imagesensor. Logic circuits 203, 223 and 243 are signal processing circuitsconfigured to process a signal obtained by photoelectric conversion ofthe photoelectric conversion element in the pixel area.

For example, as illustrated in (A) of FIG. 6 , in the solid-state imagesensor to which the photoelectric conversion element according to anembodiment of the present disclosure is applied, the pixel area 201, thecontrol circuit 202 and the logic circuit 203 may be formed in onesemiconductor chip 200.

In addition, as illustrated in (B) of FIG. 6 , the solid-state imagesensor to which the photoelectric conversion element according to anembodiment of the present disclosure is applied may be a laminated typesolid-state image sensor in which the pixel area 211 and the controlcircuit 212 are formed in a first semiconductor chip 210, and the logiccircuit 223 is formed in a second semiconductor chip 220.

Further, as illustrated in (C) of FIG. 6 , the solid-state image sensorto which the photoelectric conversion element according to an embodimentof the present disclosure is applied may be a laminated type solid-stateimage sensor in which the pixel area 231 is formed in a firstsemiconductor chip 230 and the control circuit 242 and the logic circuit243 are formed in a second semiconductor chip 240.

In the solid-state image sensors illustrated in (B) and (C) of FIG. 6 ,at least one of the control circuit and the logic circuit is formed in aseparate semiconductor chip from the semiconductor chip in which thepixel area is formed. Accordingly, since the solid-state image sensorsillustrated in (B) and (C) of FIG. 6 can extend the pixel area more thanthe solid-state image sensor illustrated in (A) of FIG. 6 , the numberof pixels accommodated in the pixel area is increased. Therefore, it ispossible to increase a plane resolution. For this reason, it is morepreferable that the solid-state image sensor to which the photoelectricconversion element according to an embodiment of the present disclosureis applied be the laminated type solid-state image sensor illustrated in(B) and (C) of FIG. 6 .

Subsequently, a specific structure of a solid-state image sensor towhich the photoelectric conversion element according to an embodiment ofthe present disclosure is applied will be described with reference toFIG. 7 . FIG. 7 is a cross sectional view illustrating an outline in aunit pixel of a solid-state image sensor to which the photoelectricconversion element according to an embodiment of the present disclosureis applied. In addition, a solid-state image sensor 300 illustrated inFIG. 7 is a rear surface irradiation type solid-state image sensor inwhich light is incident from a surface opposite to a surface in which apixel transistor and the like are formed. In addition, in FIG. 7 , withrespect to the drawing, an upper side is a light receiving surface, anda lower side is a circuit forming surface in which the pixel transistorand a peripheral circuit are formed.

As illustrated in FIG. 7 , the solid-state image sensor 300 has aconfiguration in which, in a photoelectric conversion area 320, aphotoelectric conversion element including a first photodiode PD1 formedin a semiconductor substrate 330, a photoelectric conversion elementincluding a second photodiode PD2 formed in the semiconductor substrate330 and a photoelectric conversion element including an organicphotoelectric conversion film 310 formed at a rear surface side of thesemiconductor substrate 330 are laminated in a direction of incidence oflight.

The first photodiode PD1 and the second photodiode PD2 are formed in awell area 331 that is a first conductivity type (for example, a p type)semiconductor area of the semiconductor substrate 330 made of silicon.

The first photodiode PD1 includes an n type semiconductor area 332according to a second conductivity type (for example, an n type)impurity formed at a light receiving surface side of the semiconductorsubstrate 330 and an extending portion 332 a that is formed by extendinga part thereof to reach a surface side of the semiconductor substrate330. A high concentration p type semiconductor area 334 serving as acharge accumulation layer is formed on a surface of the extendingportion 332 a. In addition, the extending portion 332 a is formed as anextraction layer for extracting a signal charge accumulated in the ntype semiconductor area 332 of the first photodiode PD1 to a surfaceside of the semiconductor substrate 330.

The second photodiode PD2 includes an n type semiconductor area 336formed at a light receiving surface side of the semiconductor substrate330 and a high concentration p type semiconductor area 338 that isformed at a surface side of the semiconductor substrate 330 and servesas a charge accumulation layer.

In the first photodiode PD1 and the second photodiode PD2, when the ptype semiconductor area is formed at an interface of the semiconductorsubstrate 330, it is possible to suppress the dark current generated atthe interface of the semiconductor substrate 330.

Here, the second photodiode PD2 formed in an area that is farthest fromthe light receiving surface is, for example, a red photoelectricconversion element that absorbs red light and performs photoelectricconversion. In addition, the first photodiode PD1 formed closer to thelight receiving surface side than the second photodiode PD2 is, forexample, a blue photoelectric conversion element that absorbs blue lightand performs photoelectric conversion.

The organic photoelectric conversion film 310 is formed on a rearsurface of the semiconductor substrate 330 through an antireflectionfilm 302 and an insulation film 306. In addition, the organicphotoelectric conversion film 310 is interposed between an upperelectrode 312 and a lower electrode 308 to form the photoelectricconversion element. Here, the organic photoelectric conversion film 310is, for example, an organic film that absorbs green light and performsphotoelectric conversion and is formed as the photoelectric conversionfilm according to an embodiment of the present disclosure describedabove. In addition, the upper electrode 312 and the lower electrode 308are made of, for example, a transparent conductive material such asindium tin oxide and indium zinc oxide.

In addition, the lower electrode 308 is connected to a vertical transferpath 348 that is formed from the rear surface side to the surface sideof the semiconductor substrate 330 through a contact plug 304penetrating the antireflection film 302. The vertical transfer path 348is formed to have a structure in which a connecting portion 340, apotential barrier layer 342, a charge accumulation layer 344 and a ptype semiconductor area 346 are laminated from the rear surface side ofthe semiconductor substrate 330.

The connecting portion 340 includes an n type impurity area of a highimpurity concentration that is formed at the rear surface side of thesemiconductor substrate 330 and is formed for an ohmic contact with thecontact plug 304. The potential barrier layer 342 includes a p typeimpurity area of a low concentration and forms a potential barrierbetween the connecting portion 340 and the charge accumulation layer344. The charge accumulation layer 344 accumulates a signal chargetransmitted from the organic photoelectric conversion film 310 and isformed in an n type impurity area of a lower concentration than theconnecting portion 340. In addition, the p type semiconductor area 346of a high concentration is formed on a surface of the semiconductorsubstrate 330. With this p type semiconductor area 346, it is possibleto suppress the dark current generated at the interface of thesemiconductor substrate 330.

Here, at the surface side of the semiconductor substrate 330, amultilayer wiring layer 350 including wires 358 laminated in a pluralityof layers is formed through an interlayer insulating layer 351. Inaddition, in the vicinity of the surface of the semiconductor substrate330, read circuits 352, 354 and 356 corresponding to the firstphotodiode PD1, the second photodiode PD2 and the organic photoelectricconversion film 310 are formed. The read circuits 352, 354 and 356 reada signal output from each photoelectric conversion element and transmitthe signal to the logic circuit (not illustrated). Further, a supportingsubstrate 360 is formed on a surface of the multilayer wiring layer 350.

On the other hand, at a light receiving surface side of the upperelectrode 312, a light shielding film 316 is formed to shield theextending portion 332 a of the first photodiode PD1 and the verticaltransfer path 348. Here, a separate area between the light shieldingfilms 316 is the photoelectric conversion area 320. In addition, anon-chip lens 318 is formed above the light shielding film 316 through aflattening film 314.

The solid-state image sensor 300 to which the photoelectric conversionelement according to an embodiment of the present disclosure is appliedhas been described above. In addition, in the solid-state image sensor300 to which the photoelectric conversion element according to anembodiment of the present disclosure is applied, since color separationis performed on a unit pixel in a longitudinal direction, a color filterand the like are not provided.

5.2. Configuration of Electronic Device

Next, a configuration of an electronic device to which the photoelectricconversion element according to an embodiment of the present disclosureis applied will be described with reference to FIG. 8 . FIG. 8 is ablock diagram illustrating a configuration of an electronic device towhich the photoelectric conversion element according to an embodiment ofthe present disclosure is applied.

As illustrated in FIG. 8 , an electronic device 400 includes an opticalsystem 402, a solid-state image sensor 404, a digital signal processor(DSP) circuit 406, a control unit 408, an output unit 412, an input unit414, a frame memory 416, a recording unit 418 and a power supply unit420.

Here, the DSP circuit 406, the control unit 408, the output unit 412,the input unit 414, the frame memory 416, the recording unit 418 and thepower supply unit 420 are connected to each other via a bus line 410.

The optical system 402 obtains incident light from an object and formsan image on an imaging surface of the solid-state image sensor 404. Inaddition, the solid-state image sensor 404 includes the photoelectricconversion element according to an embodiment of the present disclosure,converts an intensity of incident light focused on an imaging surface bythe optical system 402 into an electrical signal in units of pixels, andoutputs the result as a pixel signal.

The DSP circuit 406 processes the pixel signal transmitted from thesolid-state image sensor 404 and outputs the result to the output unit412, the frame memory 416, the recording unit 418 and the like. Inaddition, the control unit 408 includes, for example, an arithmeticprocessing circuit, and controls operations of each of the components ofthe electronic device 400.

The output unit 412 is, for example, a panel type display device such asa liquid crystal display and an organic electroluminescent display, anddisplays a video or a still image imaged by the solid-state image sensor404. Here, the output unit 412 may also include a sound output devicesuch as a speaker and a headphone. Here, the input unit 414 is, forexample, a device for inputting a user's manipulation such as a touchpanel and a button and issues manipulation commands for variousfunctions of the electronic device 400 according to the user'smanipulation.

The frame memory 416 temporarily stores the video, the still image andthe like imaged by the solid-state image sensor 404. In addition, therecording unit 418 records the video, the still image and the likeimaged by the solid-state image sensor 404 in a removable storage mediumsuch as a magnetic disk, an optical disc, a magneto optical disc and asemiconductor memory.

The power supply unit 420 appropriately supplies various types of powerserving as operating power of the DSP circuit 406, the control unit 408,the output unit 412, the input unit 414, the frame memory 416 and therecording unit 418 to these supply targets.

The electronic device 400 to which the photoelectric conversion elementaccording to an embodiment of the present disclosure is applied has beendescribed above. The electronic device 400 to which the photoelectricconversion element according to an embodiment of the present disclosureis applied may be, for example, an imaging apparatus.

6. SUMMARY

As described above, when the photoelectric conversion film according toan embodiment of the present disclosure includes the above-describedcompound, it is possible to selectively absorb light of a specificwavelength band. Accordingly, since the photoelectric conversion elementincluding the photoelectric conversion film according to an embodimentof the present disclosure has appropriate spectral characteristics asthe photoelectric conversion element of the solid-state image sensor, itis possible to increase sensitivity and a resolution of the solid-stateimage sensor.

The photoelectric conversion film according to the first embodiment ofthe present disclosure includes the quinacridone derivative representedby the above General formula (1) and the subphthalocyanine derivativerepresented by the above General formula (2). The subphthalocyaninederivative represented by the above General formula (2) has a high heatresistance, selectively absorbs green light, and has spectralcharacteristics matching the quinacridone derivative. Therefore, thephotoelectric conversion film according to the first embodiment of thepresent disclosure has sharp spectral characteristics in which greenlight is absorbed. Accordingly, since the photoelectric conversion filmaccording to the first embodiment of the present disclosure canselectively absorb green light, it is appropriate for a greenphotoelectric conversion element of the solid-state image sensor.Therefore, it is possible to increase sensitivity and a resolution ofthe solid-state image sensor.

In addition, the photoelectric conversion film according to the secondembodiment of the present disclosure includes the transparent compoundrepresented by the above General formula (3) or (4) that does not absorbvisible light. Since the transparent compound represented by the aboveGeneral formula (3) or (4) that does not absorb visible light does nothave an absorption band of visible light, there is no influence onspectral characteristics of the photoelectric conversion film.Therefore, the photoelectric conversion film formed to include thetransparent compound represented by General formula (3) or (4) and theorganic dye compound can have the same spectral characteristics as theorganic dye compound. Accordingly, since the photoelectric conversionfilm according to the second embodiment of the present disclosure canselectively absorb light that is absorbed by the organic dye compound,it is appropriate for the photoelectric conversion element of thesolid-state image sensor. Therefore, it is possible to increasesensitivity and a resolution of the solid-state image sensor.

Further, the photoelectric conversion element according to the thirdembodiment of the present disclosure includes the hole blocking layer inwhich the difference between an ionization potential of the holeblocking layer and the work function of the adjacent electrode isgreater than or equal to 2.3 eV. Since such a hole blocking layer cansuppress holes from being introduced from the electrode due to anexternal electric field, it is possible to decrease the dark current.Accordingly, since the photoelectric conversion element according to thethird embodiment of the present disclosure can suppress the darkcurrent, it is appropriate for the solid-state image sensor. It ispossible to increase sensitivity and a resolution of the solid-stateimage sensor.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

In addition, the effects described in the present specification aremerely illustrative and demonstrative, and not limitative. In otherwords, the technology according to the present disclosure can exhibitother effects that are evident to those skilled in the art along with orinstead of the effects based on the present specification.

Additionally, the present disclosure may also be configured as below.

-   -   (1)    -   A photoelectric conversion film including:    -   a quinacridone derivative represented by the following General        formula (1); and    -   a subphthalocyanine derivative represented by the following        General formula (2),

-   -   wherein, in General formula (1),    -   R₁ to R₁₀ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group, and        a substituted or unsubstituted heteroaryl group, or an aryl or        heteroaryl group formed by condensing at least two or more of        any adjacent R₁ to R₁₀, and

-   -   in General formula (2),    -   R₁₁ to R₁₆ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group, and        a substituted or unsubstituted heteroaryl group,    -   X represents any substituent selected from the group consisting        of a halogen, a hydroxy group, a thiol group, an imide group, a        substituted or unsubstituted alkoxy group, a substituted or        unsubstituted aryloxy group, a substituted or unsubstituted        alkyl group, a substituted or unsubstituted alkylthio group, and        a substituted or unsubstituted arylthio group, and    -   at least one of R₁₁ to R₁₆ represents fluorine.    -   (2)    -   The photoelectric conversion film according to (1), wherein R₁₁        to R₁₆ represent fluorine.    -   (3)    -   The photoelectric conversion film according to (1) or (2),        wherein X represents any substituent selected from the group        consisting of a halogen, a hydroxy group, a substituted or        unsubstituted alkoxy group, and a substituted or unsubstituted        aryloxy group.    -   (4)    -   The photoelectric conversion film according to any one of (1) to        (3), wherein a lowest unoccupied molecular orbital (LUMO) level        of the subphthalocyanine derivative is deeper than an LUMO level        of the quinacridone derivative, and a difference between the        LUMO level of the subphthalocyanine derivative and the LUMO        level of the quinacridone derivative is greater than or equal to        0.1 eV and less than or equal to 1.0 eV.    -   (5)    -   The photoelectric conversion film according to any one of (1) to        (4), wherein the quinacridone derivative and the        subphthalocyanine derivative form a bulk hetero film.    -   (6)    -   A photoelectric conversion film including:    -   a transparent compound that is represented by the following        General formula (3) or (4) and does not absorb visible light,

-   -   wherein, in General formula (3),    -   R₂₁ to R₃₂ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group, and        a substituted or unsubstituted heteroaryl group, or an aryl or        heteroaryl group formed by condensing at least two or more of        any adjacent R₂₁ to R₃₂, and    -   in General formula (4),    -   R₄₁ to R₄₈ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, an imide group, a carboxy        group, a carboxamido group, a carboalkoxy group, a substituted        or unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group, and        a substituted or unsubstituted heteroaryl group, or an aryl or        heteroaryl group formed by condensing at least two or more of        any adjacent R₄₁ to R₄₈, and    -   Ar₁ to Ar₄ each independently represent a substituted or        unsubstituted aryl group or a substituted or unsubstituted        heteroaryl group.    -   (7)    -   The photoelectric conversion film according to (6), wherein R₂₁,        R₂₄, R₂₅, R₂₈, R₂₉, and R₃₂ represent hydrogen in General        formula (3).    -   (8)    -   The photoelectric conversion film according to (6), wherein at        least one of substituents of Ar₁ to Ar₄ and R₄₁ to R₄₈ is an        electron attracting group in General formula (4).    -   (9)    -   The photoelectric conversion film according to (8), wherein the        electron attracting group is any substituent selected from the        group consisting of a halogen, a cyano group, a nitro group, a        sulfonyl group, an arylsulfonyl group, an alkylsulfonyl group,        an acyl group, an acylamino group, an acyloxy group, an imide        group, a carboxy group, a carboxamido group, a carboalkoxy        group, a halogenated alkyl group, and a halogenated aryl group.    -   (10)    -   The photoelectric conversion film according to any one of (6) to        (9), further including:    -   an organic dye compound,    -   wherein the organic dye compound and the compound represented by        General formula (3) or General formula (4) form a bulk hetero        film.    -   (11)    -   The photoelectric conversion film according to (10), wherein the        organic dye compound is a compound that absorbs green light        having a wavelength band of greater than or equal to 450 nm and        less than or equal to 600 nm.    -   (12)    -   The photoelectric conversion film according to (10) or (11),        wherein the organic dye compound is a quinacridone derivative        represented by the following General formula (1),

-   -   wherein, in General formula (1),    -   R₁ to R₁₀ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group, and        a substituted or unsubstituted heteroaryl group, or an aryl or        heteroaryl group formed by condensing at least two or more of        any adjacent R₁ to R₁₀.    -   (13)    -   The photoelectric conversion film according to (12), wherein an        LUMO level of the compound represented by General formula (3)        or (4) is deeper than an LUMO level of the quinacridone        derivative, and a difference between the LUMO level of the        compound represented by General formula (3) or (4) and the LUMO        level of the quinacridone derivative is greater than or equal to        0.1 eV and less than or equal to 1.0 eV.    -   (14)    -   A photoelectric conversion element including:    -   a photoelectric conversion film;    -   a pair of electrodes that are disposed at both sides of the        photoelectric conversion film, which is interposed therebetween;        and    -   a hole blocking layer disposed between the photoelectric        conversion film and one of the electrodes,    -   wherein a difference between an ionization potential of the hole        blocking layer and a work function of one of the electrodes, the        one being adjacent to the hole blocking layer, is greater than        or equal to 2.3 eV.    -   (15)    -   The photoelectric conversion element according to (14), wherein        the hole blocking layer includes a compound represented by the        following General formula (5),

-   -   wherein, in General formula (5),    -   R₅₀ represents any substituent selected from the group        consisting of hydrogen, a halogen, a hydroxy group, an alkoxy        group, a cyano group, a nitro group, a silylalkyl group, a        silylalkoxy group, an arylsilyl group, a thioalkyl group, a        thioaryl group, a sulfonyl group, an arylsulfonyl group, an        alkylsulfonyl group, an amino group, an alkylamino group, an        arylamino group, an acyl group, an acylamino group, an acyloxy        group, a carboxy group, a carboxamido group, a carboalkoxy        group, a substituted or unsubstituted alkyl group, a substituted        or unsubstituted cycloalkyl group, a substituted or        unsubstituted aryl group, and a substituted or unsubstituted        heteroaryl group, and Ar₅ to Ar₈ represent a substituted or        unsubstituted heteroaryl group.    -   (16)    -   The photoelectric conversion element according to (15), wherein        at least one of substituents of Ar₅ to Ar₈ and R₅₀ is an        electron attracting group.    -   (17)    -   The photoelectric conversion element according to (16), wherein        the electron attracting group is any substituent selected from        the group consisting of a halogen, a cyano group, a nitro group,        a sulfonyl group, an arylsulfonyl group, an alkylsulfonyl group,        an acyl group, an acylamino group, an acyloxy group, an imide        group, a carboxy group, a carboxamido group, a carboalkoxy        group, a halogenated alkyl group, and a halogenated aryl group.    -   (18)    -   The photoelectric conversion element according to (15), wherein        the compound represented by General formula (5) is a compound        represented by any of the following structural formulas.

-   -   (19)    -   The photoelectric conversion element according to any one        of (14) to (18), wherein the hole blocking layer has a thickness        of greater than or equal to 5 nm and less than or equal to 20        nm.    -   (20)    -   The photoelectric conversion element according to any one        of (14) to (19), wherein one adjacent electrode is a transparent        electrode.    -   (21)    -   The photoelectric conversion element according to (20), wherein        one adjacent electrode includes at least one of indium tin oxide        and indium zinc oxide.    -   (22)    -   A solid-state image sensor including a photoelectric conversion        film that includes a quinacridone derivative represented by the        following General formula (1) and a subphthalocyanine derivative        represented by the following General formula (2).

-   -   In General formula (1),    -   R₁ to R₁₀ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group and        a substituted or unsubstituted heteroaryl group or an aryl or        heteroaryl group formed by condensing at least two or more of        any adjacent R₁ to R₁₀.

-   -   In General formula (2),    -   R₁₁ to R₁₆ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group and        a substituted or unsubstituted heteroaryl group,    -   X represents any substituent selected from the group consisting        of a halogen, a hydroxy group, a thiol group, an imide group, a        substituted or unsubstituted alkoxy group, a substituted or        unsubstituted aryloxy group, a substituted or unsubstituted        alkyl group, a substituted or unsubstituted alkylthio group and        a substituted or unsubstituted arylthio group, and    -   at least one of R₁₁ to R₁₆ represents fluorine.    -   (23)    -   A solid-state image sensor including a photoelectric conversion        film containing a transparent compound that is represented by        the following General formula (3) or (4)    -   and does not absorbs visible light.

-   -   In General formula (3),    -   R₂₁ to R₃₂ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group and        a substituted or unsubstituted heteroaryl group or an aryl or        heteroaryl group formed by condensing at least two or more of        any adjacent R₂₁ to R₃₂,    -   in General formula (4),    -   R₄₁ to R₄₈ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, an imide group, a carboxy        group, a carboxamido group, a carboalkoxy group, a substituted        or unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group and        a substituted or unsubstituted heteroaryl group or an aryl or        heteroaryl group formed by condensing at least two or more of        any adjacent R₄₁ to R₄₈, and    -   Ar₁ to Ar₄ each independently represent a substituted or        unsubstituted aryl group or a substituted or unsubstituted        heteroaryl group.    -   (24)    -   A solid-state image sensor including:    -   a photoelectric conversion element containing,    -   a photoelectric conversion film,    -   a pair of electrodes that are disposed at both sides of the        photoelectric conversion film, which is interposed therebetween,        and    -   a hole blocking layer disposed between the photoelectric        conversion film and one of the electrodes,    -   wherein a difference between an ionization potential of the hole        blocking layer and a work function of one adjacent electrode is        greater than or equal to 2.3 eV.    -   (25)    -   The solid-state image sensor according to any one of (22) to        (24), wherein the photoelectric conversion film includes an        organic dye compound that absorbs green light having a        wavelength of band of greater than or equal to 450 nm and less        than or equal to 600 nm and performs photoelectric conversion on        the absorbed green light.    -   (26)    -   The solid-state image sensor according to any one of (22)        to (24) configured as a laminated type solid-state image sensor        that includes a first chip in which the photoelectric conversion        film is formed and a second chip in which a signal processing        circuit configured to process a signal obtained by photoelectric        conversion by the photoelectric conversion film is formed and        that is laminated on the first chip.    -   (27)    -   An electronic device including:    -   a solid-state image sensor containing a photoelectric conversion        film having a quinacridone derivative represented by the        following General formula (1) and a subphthalocyanine derivative        represented by the following General formula (2);    -   an optical system configured to guide incident light to the        solid-state image sensor; and    -   an arithmetic processing circuit configured to arithmetically        process a signal output from the solid-state image sensor.

-   -   In General formula (1),    -   R₁ to R₁₀ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group and        a substituted or unsubstituted heteroaryl group or an aryl or        heteroaryl group formed by condensing at least two or more of        any adjacent R₁ to R₁₀.

-   -   In General formula (2),    -   R₁₁ to R₁₆ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group and        a substituted or unsubstituted heteroaryl group,    -   X represents any substituent selected from the group consisting        of a halogen, a hydroxy group, a thiol group, an imide group, a        substituted or unsubstituted alkoxy group, a substituted or        unsubstituted aryloxy group, a substituted or unsubstituted        alkyl group, a substituted or unsubstituted alkylthio group and        a substituted or unsubstituted arylthio group, and    -   at least one of R₁₁ to R₁₆ represents fluorine.    -   (28)    -   An electronic device including:    -   a solid-state image sensor including a photoelectric conversion        film containing a transparent compound that is represented by        the following General formula (3) or (4)    -   and does not absorb visible light;    -   an optical system configured to guide incident light to the        solid-state image sensor; and    -   an arithmetic processing circuit configured to arithmetically        process a signal output from the solid-state image sensor.

-   -   In General formula (3),    -   R₂₁ to R₃₂ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group and        a substituted or unsubstituted heteroaryl group or an aryl or        heteroaryl group formed by condensing at least two or more of        any adjacent R₂₁ to R₃₂, and    -   in General formula (4),    -   R₄₁ to R₄₈ each independently represent any substituent selected        from the group consisting of hydrogen, a halogen, a hydroxy        group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, an imide group, a carboxy        group, a carboxamido group, a carboalkoxy group, a substituted        or unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group and        a substituted or unsubstituted heteroaryl group or an aryl or        heteroaryl group formed by condensing at least two or more of        any adjacent R₄₁ to R₄₈, and    -   Ar₁ to Ar₄ each independently represent a substituted or        unsubstituted aryl group or a substituted or unsubstituted        heteroaryl group.    -   (29)    -   An electronic device including:    -   a solid-state image sensor including a photoelectric conversion        element that contains a photoelectric conversion film, a pair of        electrodes that are disposed at both sides of the photoelectric        conversion film, which is interposed therebetween, and a hole        blocking layer disposed between the photoelectric conversion        film and one of the electrodes, wherein the difference between        an ionization potential of the hole blocking layer and a work        function of one adjacent electrode is greater than or equal to        2.3 eV;    -   an optical system configured to guide incident light to the        solid-state image sensor; and    -   an arithmetic processing circuit configured to arithmetically        process a signal output from the solid-state image sensor.    -   (30)    -   A photoelectric conversion film including:    -   a quinacridone derivative represented by General formula (1):

-   -    and    -   a subphthalocyanine derivative represented by General formula        (2):

-   -   where in General formula (1), R₁ to R₁₀ are each independently        selected from the group consisting of hydrogen, a halogen, a        hydroxy group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group, a        substituted or unsubstituted heteroaryl group, and an aryl or        heteroaryl group formed by condensing at least two of the R₁ to        R₁₀ that are adjacent to one another,    -   where in General formula (2), R₁₁ to R₁₆ are each independently        selected from the group consisting of hydrogen, a halogen, a        hydroxy group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group, and        a substituted or unsubstituted heteroaryl group,    -   where X is selected from the group consisting of a halogen, a        hydroxy group, a thiol group, an imide group, a substituted or        unsubstituted alkoxy group, a substituted or unsubstituted        aryloxy group, a substituted or unsubstituted alkyl group, a        substituted or unsubstituted alkylthio group, and a substituted        or unsubstituted arylthio group, and where at least one of R₁₁        to R₁₆ represents fluorine.    -   (31) The photoelectric conversion film according to (30), where        R₁₁ to R₁₆ are each fluorine.    -   (32)    -   The photoelectric conversion film according to any one of (30)        to (31), where X is selected from the group consisting of a        halogen, a hydroxy group, a substituted or unsubstituted alkoxy        group, and a substituted or unsubstituted aryloxy group.    -   (33)    -   The photoelectric conversion film according to any one of (30)        to (32), where a lowest unoccupied molecular orbital (LUMO)        level of the subphthalocyanine derivative is deeper than a LUMO        level of the quinacridone derivative, and a difference between        the LUMO level of the subphthalocyanine derivative and the LUMO        level of the quinacridone derivative is greater than or equal to        0.1 eV and less than or equal to 1.0 eV.    -   (34)    -   The photoelectric conversion film according to any one of (30)        to (33), where the quinacridone derivative and the        subphthalocyanine derivative are a bulk hetero film.    -   (35)    -   A photoelectric conversion film including:    -   a transparent compound that does not absorb visible light and        that is represented by at least one of General formula (3) and        General formula (4):

-   -   where in General formula (3), R₂₁ to R₃₂ are each independently        selected from the group consisting of hydrogen, a halogen, a        hydroxy group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group, a        substituted or unsubstituted heteroaryl group, and an aryl or        heteroaryl group formed by condensing at least two of the R₂₁ to        R₃₂ that are adjacent to one another, and    -   where in General formula (4), R₄₁ to R₄₈ are each independently        selected from the group consisting of hydrogen, a halogen, a        hydroxy group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, an imide group, a carboxy        group, a carboxamido group, a carboalkoxy group, a substituted        or unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group, a        substituted or unsubstituted heteroaryl group, and an aryl or        heteroaryl group formed by condensing at least two of the R₄₁ to        R₄₈ that are adjacent to one another, and where Ar₁ to Ar₄ are        each independently one of a substituted or unsubstituted aryl        group and a substituted or unsubstituted heteroaryl group.    -   (36)    -   The photoelectric conversion film according to (35), where the        transparent compound is represented by at least General        formula (3) and R₂₁, R₂₄, R₂₅, R₂₈, R₂₉, and R₃₂ are each        hydrogen in General formula (3).    -   (37)    -   The photoelectric conversion film according to any one of (35)        to (36), where the transparent compound is represented by at        least General formula (4) and at least one of Ar₁ to Ar₄ and R₄₁        to R₄₈ is an electron attracting group in General formula (4).    -   (38)    -   The photoelectric conversion film according to any one of (35)        to (37), where the electron attracting group is selected from        the group consisting of a halogen, a cyano group, a nitro group,        a sulfonyl group, an arylsulfonyl group, an alkylsulfonyl group,        an acyl group, an acylamino group, an acyloxy group, an imide        group, a carboxy group, a carboxamido group, a carboalkoxy        group, a halogenated alkyl group, and a halogenated aryl group.    -   (39)    -   The photoelectric conversion film according to any one of (35)        to (38), further including:    -   an organic dye compound, where the organic dye compound and the        compound represented by the at least one of General formula (3)        and General formula (4) are a bulk hetero film.    -   (40)    -   The photoelectric conversion film according to any one of (35)        to (39), where the organic dye compound absorbs green light        having a wavelength band of greater than or equal to        approximately 450 nm and less than or equal to approximately 600        nm.    -   (41)    -   The photoelectric conversion film according to any one of (35)        to (40), where the organic dye compound is a quinacridone        derivative represented by General formula (1):

-   -   where in General formula (1), R₁ to R₁₀ are each independently        selected from the group consisting of hydrogen, a halogen, a        hydroxy group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group, a        substituted or unsubstituted heteroaryl group, and an aryl or        heteroaryl group formed by condensing at least two of the R₁ to        R₁₀ that are adjacent to one another.    -   (42)    -   The photoelectric conversion film according to any one of (35)        to (41), where a LUMO level of the at least one of the General        formula (3) and the General formula (4) is deeper than a LUMO        level of the quinacridone derivative, and a difference between        the LUMO level of the at least one of the General formula (3)        and the General formula (4) and the LUMO level of the        quinacridone derivative is greater than or equal to 0.1 eV and        less than or equal to 1.0 eV.    -   (43)    -   A photoelectric conversion element including:    -   a photoelectric conversion film;    -   a pair of electrodes that are disposed at both sides of the        photoelectric conversion film, which is interposed therebetween;        and    -   a hole blocking layer disposed between the photoelectric        conversion film and one of the electrodes, where a difference        between an ionization potential of the hole blocking layer and a        work function of the one of the electrodes is greater than or        equal to 2.3 eV.    -   (44)    -   The photoelectric conversion element according to (43), where        the hole blocking layer includes a compound represented by        General formula (5):

-   -   where in General formula (5), R₅₀ is selected from the group        consisting of hydrogen, a halogen, a hydroxy group, an alkoxy        group, a cyano group, a nitro group, a silylalkyl group, a        silylalkoxy group, an arylsilyl group, a thioalkyl group, a        thioaryl group, a sulfonyl group, an arylsulfonyl group, an        alkylsulfonyl group, an amino group, an alkylamino group, an        arylamino group, an acyl group, an acylamino group, an acyloxy        group, a carboxy group, a carboxamido group, a carboalkoxy        group, a substituted or unsubstituted alkyl group, a substituted        or unsubstituted cycloalkyl group, a substituted or        unsubstituted aryl group, and a substituted or unsubstituted        heteroaryl group, and where Ar₅ to Ar₈ each represent a        substituted or unsubstituted heteroaryl group.    -   (45)    -   The photoelectric conversion element according to any one        of (43) to (44), where at least one of the Ar₅ to Ar₈ and R₅₀ is        an electron attracting group.    -   (46)    -   The photoelectric conversion element according to any one        of (43) to (45), where the electron attracting group is selected        from the group consisting of a halogen, a cyano group, a nitro        group, a sulfonyl group, an arylsulfonyl group, an alkylsulfonyl        group, an acyl group, an acylamino group, an acyloxy group, an        imide group, a carboxy group, a carboxamido group, a carboalkoxy        group, a halogenated alkyl group, and a halogenated aryl group.    -   (47)    -   The photoelectric conversion element according to any one        of (43) to (46), where the General formula (5) is any of the        following structural formulas:

-   -   (48)    -   The photoelectric conversion element according to any one        of (43) to (47), where the hole blocking layer has a thickness        of greater than or equal to approximately 5 nm and less than or        equal to approximately 20 nm.    -   (49)    -   An electronic device including:    -   a photoelectric conversion film that includes:    -   a quinacridone derivative represented by General formula (1):

-   -    and    -   a subphthalocyanine derivative represented by General formula        (2):

-   -   where in General formula (1), R₁ to R₁₀ are each independently        selected from the group consisting of hydrogen, a halogen, a        hydroxy group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group, a        substituted or unsubstituted heteroaryl group, and an aryl or        heteroaryl group formed by condensing at least two of the R₁ to        R₁₀ that are adjacent to one another;    -   where in General formula (2), R₁₁ to R₁₆ are each independently        selected from the group consisting of hydrogen, a halogen, a        hydroxy group, an alkoxy group, a cyano group, a nitro group, a        silylalkyl group, a silylalkoxy group, an arylsilyl group, a        thioalkyl group, a thioaryl group, a sulfonyl group, an        arylsulfonyl group, an alkylsulfonyl group, an amino group, an        alkylamino group, an arylamino group, an acyl group, an        acylamino group, an acyloxy group, a carboxy group, a        carboxamido group, a carboalkoxy group, a substituted or        unsubstituted alkyl group, a substituted or unsubstituted        cycloalkyl group, a substituted or unsubstituted aryl group, and        a substituted or unsubstituted heteroaryl group;    -   where X is selected from the group consisting of a halogen, a        hydroxy group, a thiol group, an imide group, a substituted or        unsubstituted alkoxy group, a substituted or unsubstituted        aryloxy group, a substituted or unsubstituted alkyl group, a        substituted or unsubstituted alkylthio group, and a substituted        or unsubstituted arylthio group; and    -   where at least one of R₁₁ to R₁₆ represents fluorine.

REFERENCE SIGNS LIST

-   -   100 photoelectric conversion element    -   102 substrate    -   104 lower electrode    -   106 electron blocking layer    -   108 photoelectric conversion layer    -   110 hole blocking layer    -   112 upper electrode

1-20. (canceled)
 21. A photoelectric conversion element comprising: aphotoelectric conversion film; a pair of electrodes that are disposed atboth sides of the photoelectric conversion film, which is interposedtherebetween; and a hole blocking layer disposed between thephotoelectric conversion film and one of the electrodes, wherein adifference between an ionization potential of the hole blocking layerand a work function of the one of the electrodes is greater than orequal to 2.3 eV.
 22. The photoelectric conversion element according toclaim 21, wherein the hole blocking layer includes a compoundrepresented by General formula (5):

wherein in General formula (5), R50 is selected from the groupconsisting of hydrogen, a halogen, a hydroxy group, an alkoxy group, acyano group, a nitro group, a silylalkyl group, a silylalkoxy group, anarylsilyl group, a thioalkyl group, a thioaryl group, a sulfonyl group,an arylsulfonyl group, an alkylsulfonyl group, an amino group, analkylamino group, an arylamino group, an acyl group, an acylamino group,an acyloxy group, a carboxy group, a carboxamido group, a carboalkoxygroup, a substituted or unsubstituted alkyl group, a substituted orunsubstituted cycloalkyl group, a substituted or unsubstituted arylgroup, and a substituted or unsubstituted heteroaryl group, and whereinAr5 to Ar8 each represent a substituted or unsubstituted heteroarylgroup.
 23. The photoelectric conversion element according to claim 22,wherein at least one of the Ar5 to Ar8 and R50 is an electron attractinggroup.
 24. The photoelectric conversion element according to claim 23,wherein the electron attracting group is selected from the groupconsisting of the halogen, the cyano group, the nitro group, thesulfonyl group, the arylsulfonyl group, the alkylsulfonyl group, theacyl group, the acylamino group, the acyloxy group, an imide group, thecarboxy group, the carboxamido group, the carboalkoxy group, ahalogenated alkyl group, and a halogenated aryl group.
 25. Thephotoelectric conversion element according to claim 22, wherein theGeneral formula (5) is any of the following structural formulas:


26. The photoelectric conversion element according to claim 21, whereinthe hole blocking layer has a thickness of greater than or equal toapproximately 5 nm and less than or equal to approximately 20 nm. 27.The photoelectric conversion element according to claim 21, wherein theone of the electrodes is formed of one of indium tin oxide, indium zincoxide, and graphene.
 28. The photoelectric conversion element accordingto claim 27, wherein the one of the electrodes is formed of indium tinoxide.
 29. The photoelectric conversion element according to claim 21,wherein the photoelectric conversion film comprises a p-typephotoelectric conversion material and an n-type photoelectric conversionmaterial, the p-type photoelectric conversion material and the n-typephotoelectric conversion material being a bulk hetero mixed film. 30.The photoelectric conversion film according to claim 29, wherein thebulk hetero mixed film is a film having a microstructure in which one ofthe p-type photoelectric conversion material and the n-typephotoelectric conversion material is in a crystal fine particle stateand the other is in an amorphous state.
 31. The photoelectric conversionfilm according to claim 29, wherein the bulk hetero mixed film is a filmhaving a microstructure in which both the p type photoelectricconversion material and the n type photoelectric conversion material arein a fine crystalline state.
 32. An electronic device comprising aphotoelectric conversion film according to claim 21.